Skip to main content

Full text of "A manual of carpentry and joinery"

See other formats 


Google 


This  is  a  digital  copy  of  a  book  that  was  preserved  for  generations  on  library  shelves  before  it  was  carefully  scanned  by  Google  as  part  of  a  project 

to  make  the  world's  books  discoverable  online. 

It  has  survived  long  enough  for  the  copyright  to  expire  and  the  book  to  enter  the  public  domain.  A  public  domain  book  is  one  that  was  never  subject 

to  copyright  or  whose  legal  copyright  term  has  expired.  Whether  a  book  is  in  the  public  domain  may  vary  country  to  country.  Public  domain  books 

are  our  gateways  to  the  past,  representing  a  wealth  of  history,  culture  and  knowledge  that's  often  difficult  to  discover. 

Marks,  notations  and  other  maiginalia  present  in  the  original  volume  will  appear  in  this  file  -  a  reminder  of  this  book's  long  journey  from  the 

publisher  to  a  library  and  finally  to  you. 

Usage  guidelines 

Google  is  proud  to  partner  with  libraries  to  digitize  public  domain  materials  and  make  them  widely  accessible.  Public  domain  books  belong  to  the 
public  and  we  are  merely  their  custodians.  Nevertheless,  this  work  is  expensive,  so  in  order  to  keep  providing  tliis  resource,  we  liave  taken  steps  to 
prevent  abuse  by  commercial  parties,  including  placing  technical  restrictions  on  automated  querying. 
We  also  ask  that  you: 

+  Make  non-commercial  use  of  the  files  We  designed  Google  Book  Search  for  use  by  individuals,  and  we  request  that  you  use  these  files  for 
personal,  non-commercial  purposes. 

+  Refrain  fivm  automated  querying  Do  not  send  automated  queries  of  any  sort  to  Google's  system:  If  you  are  conducting  research  on  machine 
translation,  optical  character  recognition  or  other  areas  where  access  to  a  large  amount  of  text  is  helpful,  please  contact  us.  We  encourage  the 
use  of  public  domain  materials  for  these  purposes  and  may  be  able  to  help. 

+  Maintain  attributionTht  GoogXt  "watermark"  you  see  on  each  file  is  essential  for  in  forming  people  about  this  project  and  helping  them  find 
additional  materials  through  Google  Book  Search.  Please  do  not  remove  it. 

+  Keep  it  legal  Whatever  your  use,  remember  that  you  are  responsible  for  ensuring  that  what  you  are  doing  is  legal.  Do  not  assume  that  just 
because  we  believe  a  book  is  in  the  public  domain  for  users  in  the  United  States,  that  the  work  is  also  in  the  public  domain  for  users  in  other 
countries.  Whether  a  book  is  still  in  copyright  varies  from  country  to  country,  and  we  can't  offer  guidance  on  whether  any  specific  use  of 
any  specific  book  is  allowed.  Please  do  not  assume  that  a  book's  appearance  in  Google  Book  Search  means  it  can  be  used  in  any  manner 
anywhere  in  the  world.  Copyright  infringement  liabili^  can  be  quite  severe. 

About  Google  Book  Search 

Google's  mission  is  to  organize  the  world's  information  and  to  make  it  universally  accessible  and  useful.   Google  Book  Search  helps  readers 
discover  the  world's  books  while  helping  authors  and  publishers  reach  new  audiences.  You  can  search  through  the  full  text  of  this  book  on  the  web 

at|http: //books  .google  .com/I 


A    MANUAL    OF    CARPENTRY 
AND    JOINERY 


A    MANUAL    OF 

CARPENTJ^Y   AND 

JOINERY 


BY 


J.  W.   RILEY 


LECTURER  IN  DESCRIPTIVE   GEOMETRY,   BUILDING  CONSTRUCTION, 

AND  CARPENTRY  AND  JOINERY,   AT  THE  MUNICIPAL 

TECHNICAL  SCHOOL,   ROCHDALE 


WITH  995  ILLUSTRATIONS 


"     ■        -  '  rf     •      • 


MACMILLAN    AND   CO.,    Limited 

NEW  YORK  :  THE  MACMILLAN  COMPANY 

1905 


All  rights  reseroed 


4.    •  *  W     4  I,    *■ 

:  c    .  J  ^ . .  u  ^ . . 


THK  N!:w  YORK 

fu::liCub:;aryj 
371167 

ASTOR,  L!^^''  X  A^"0 

H  V  L  ! 


OLASOOW  :    PRINTED   AT   THE    UNIVERSITY    PRESS 
BY   ROBERT   MACLKHOSE   AND   CO.    LTD. 


PREFACE. 

In  writing  this  book  the  needs  of  carpenters  and  joiners 
who  are  studying  the  scientific  principles  of  their  work 
have  been  borne  in  mind  throughout.  Students  who  are 
attending  classes  at  Technical  Institutes  to  prepare  for  the 
examinations  of  the  City  and  Guilds  of  London  Institute  in 
Carpentry  and  Joinery  will  find  that  the  following  chapters 
have  the  same  aims  as  their  syllabus,  inasmuch  as  they  are 
intended  to  develop  an  appreciation  of  general  principles 
rather  than  to  encourage  empirical  methods  of  work.  In 
fact,  the  educational  ideal  underlying  the  syllabus  of  the 
City  and  Guilds  of  London  Institute  has  constantly  guided 
the  author. 

The  simplest  types  of  construction  have  been  dealt  with 
most  fully,  and  the  principles  they  embody  have  been 
emphasised  continually.  Without  going  into  great  detail, 
these  rules  have  then  been  applied  to  more  complicated 
examples ;  for  a  long  experience  has  convinced  the  author 
that  a  student  who  has  grasped  the  fundamental  facts  of  a 
subject  requires  a  minimum  of  guidance  in  more  advanced 
work. 

Unusual  prominence  has  been  given  to  the  elementary 
parts  of  geometry,  mensuration,  and  mechanics,  because 
students  of  Carpentry  and  Joinery  constantly  begin  their 
work  without  this  necessary  preliminary  knowledge. 
Among  other  special  features  of  the  book  are  the  chapters 


vi  PREFACE 

on  tools  and  woodworking  machinery  as  well  as  the  large 
number  of  pictorial  diagrams  of  details  of  construction. 

It  is  hoped  that  in  addition  to  its  use  by  students  of 
technical  classes  the  book  will  be  of  service  to  practical 
men  in  the  workshop  and  to  schoolmasters  framing  courses 
of  manual  training. 

Summaries  are  given  at  the  ends  of  the  chapters,  and 
ample  material  for  testing  the  knowledge  of  the  student 
will  be  found  in  the  questions — chiefly  derived  from  past 
examination  papers  of  the  City  and  Guilds  of  London 
Institute — which  immediately  follow  the  summaries. 

Acknowledgement  is  gladly  made  of  indebtedness  to 
Messrs.  William  Marples  &  Sons,  Ltd.,  Sheffield,  and  to 
Messrs.  Joseph  Gleave  &  Son,  Manchester,  for  permission 
to  use  illustrations  of  tools  from  their  catalogues ;  also 
to  Messrs.  Thomas  Kobinson  &  Sons,  Ltd.,  of  Kochdale, 
for  all  the  photographs  of  wood-working  machines  which 
illustrate  Chapter  VI.  Thanks  are  gratefully  tendered 
to  Mr.  E.  Holden,  Principal  of  the  Municipal  Technical 
School,  Newry,  Co.  Down,  for  reading  the  proofs  and 
making  many  valuable  suggestions  during  the  passage  of 
the  work  through  the  press. 

It  is  a  great  pleasure  to  acknowledge,  in  conclusion,  the 
generous  help  which  has  been  received,  throughout  the 
whole  period  of  preparation  of  the  book,  from  Prof.  R.  A. 
Gregory  and  Mr.  A.  T.  Simmons,  B.Sc.  Their  kindly 
criticism  and  advice,  and  the  advantage  of  their  wide 
experience  have  very  materially  lessened  the  difficulties  of 
the  author's  task. 

J.  W.  RILEY. 

Rochdale. 


CONTENTS. 

PAoa 
CHAPTER  I. 

Timber, 1 

CHAPTER  II. 
Plane  Geometry, 21 

CHAPTER  III. 
Solid  Geometry,  -  49 

CHAPTER  IV. 

Mensuration  op  Carpentry  and  Joinery,         -        -  85 

CHAPTER  V. 
Tools, -      107 

CHAPTER  VI. 
Woodworking  Machinery,  ....  -      129 

CHAPTER  VII. 
Joints  and  Fastenings, 158 

CHAPTER  Vin. 
Wooden  Floors, -      193 

CHAPTER  IX. 
WooDBN  Roofs, 215 


viii  CONTENTS 

PA0B2 

CHAPTER  X. 
Partitions  and  Wooden  Framed  Buildings,     -  -      259 

CHAPTER  XL 
Miscellaneous  Carpentry  Constructions,  274 

CHAPTER  XII. 
Mechanics  of  Carpentry, 306 

CHAPTER  XIII. 
Doors  and  other  Panelled  Framing,        ....      346 

CHAPTER  XIV. 
Windows, 381 

CHAPTER  XV. 
Roof-lights  and  Conservatories,       -  ...      412 

CHAPTER  XVI. 
Staircase  Work  and  Handrailing, 430    ' 

CHAPTER  XVII. 
Workshop  Practice  and  Special  Constructions,      -        -      460 

Technological  Examination  Papers,  1905,  483 

Answers, 491 

Index, 492 


^■fn 


A  MANUAL  OF 
CARPENTRY   AND  JOINERY. 


TIMBEB. 


TllO  Source  of  Timber, —Tlie  *oud  used  by  tbe  carpenter  and 
joiner  is  obtaioed  from  the  plants  known  as  treea.  In  tropical 
countries  palms  and  grasties  (e.g.  bamboo)  gi'ow  to  greiit  size, 
but  the  atems  of  theae  plants  are  unHnitable  for  timber.  In 
temperitte  climatea  most  forest  treea  are  of  a  quite  diSerent 
typ<i,  belonging  either  to  the  class  which  includes  the  oak,  ash, 
beech,  birch,  etc.,  or  to  that  known  as  the  conifei's,  among 
which  are  the  pines  and  firs.  It  ia  auch  treea  alone  which  yield 
timber  uaad  by  wood-workera. 

Xbe  Structure  of  the  Stem  of  the  Oak.—  If  a  branch  or 
stem  of  an  oak  tree  be  cut  across,  it  will  be  seen  to 
'conaiat  of  (a)  a  ceatnil  pith  ;  (6)  layers  of  wood ;  (c)  bark, 
conaiating  of  an  outer  part  corapoHed  of  corky  and  dead  layers, 
and  an  inner  part  of  bast  which  can  be  torn  off  in  shreds  ;  and 
(li)  a  thin  layer  between  the  bast  and  the  wood  called  cambium 
which,  by  diTidiog,  forms  new  layers  of  wood  on  its  inner  aide 
and  new  layers  of  baat  on  ita  outer  aide.  Tlie  cambium  is  moat 
active  in  spring  and  early  summer,  and  the  new  wood  then 
formed  ia  of  open  texture.  Ae  autumn  approachea  the  activity 
of  the  cambium  decreases,  and  the  wood  it  forms  is  close  in 
Uxture  and  small  in  amount.  In  the  winter  the  division  of 
the  cambium  stops  altogether,  to  be  renewed  in  spring  by  the 
formation  of  more  open-tcKtured  wood.  The  difference  in  the 
appearance  of  the  autumn  wood  of  one  year  and  the  spring 
wood  of  the  next  is  so  marked  that  it  ia  easy  lo  diatrngaS^  'Ca% 


2  A  MANUAL  OP  CARPENTRY   AND  JOINERY. 

liinita  of  tlie  wood  formed  in  one  year.  The  layer  of  wood 
formed  in  one  year  is  called  an  annaai  ring.  The  bast  is  soft 
and  becomes  squeezed  up  under  the  bark  so  that  it  ia  not  at  all 
conspicuous. 

Id  such  a  cross  section  aa  that  described  may  be  seen,  stretch- 
ing from  the  pith  to  the  bark,  a  number  of  radial  lines  of  tissue 


which  are  called  mednlluy  rays,  A  comparison  of  such  a  trans- 
verse section  with  wood  cut  in  other  directions  shows  that  the 
medullary  rays  are  really  thin  lath-like  plates  arranged  radially. 
lu    a   radial    longitudinal  section  of  the  wood  (Fig.   1)  the 


medullary  rays  nhow  as  Btlvery  patches  on  the  Rurface,  giving 
the  appearance  known  as  silver  grain.  In  niost  kinds  of  wood 
the  medullary  rays — though  really  present— are  not  distinguish- 
able by  the  naked  eye  ;  they  are  most  clearly  seen  in  the  oak 
and  the  beech.  In  a.  section  of  an  older  oak  (Fig.  2)  it  will  be 
seen  that  the  wood  consists  of  two  well-maiked  partn  :  an  inner 
heMtwood,  dark  in  colour  and  hard ;  and  an  outer  Hqiwood, 


lighter  in  colour  iiud  of  sDiiiowhat  aponfiy  I 
diffiirence  is  explained 
hj  tbe  fact  that  tliu 
heartwood  is  dead  and 
of  no  wse  to  tlie  tree 
except  aa  a  niealiauiuil 
■upport  ;  while  tbe 
Mpwood  is  Htill  ac- 
tively alive  and  con- 
veying up  the  trunk 
tlie  water  and  minei-al 
food  which  the  routs 
take    op     from     the 

The  heartwood,  al- 
though dead  so  far  as 
the  life  of  the  tree  ia 
concerned,   ia  the   only    part   of   the    tree    which    i 


uitable 


for   1 


■uire  ( 


for   constructional   purpoaea. 

When  a  tree  begins  to  decay, 
the  heartwood,  being  the  oldest, 
is  naturally  tbe  first  to  suffer. 
Ti'eeB  cut  down  before  they  have 
attained  maturity  are  likely  to 
have  an  over- al.iun dance  of  sap- 

Sapwood  ia  unsuitable  for  use 
on  account  of  itK  soft  spongy 
texture,  and  its  liability  to 
abaorb  moisture. 

The  Timber  of  other  Trees. 
— Although  tbe  above  descrip- 
tion of  the  oak  applies  also,  in 
its    general    features,   to   other 
*  '     *  .     "  limber- pioduc Lug    trees,    there 

«<j"d    »  1.  *  are   many  -respects  in  which  a 

"*    iDBd   j^  roji  marked  difference  is  ol>sei'vable. 

w-jd.    ,Pl,. In   the  pinep,,  Rr^  and   larches 

(Fig.  3),  tbe  annual  rings  ai-e 
'learly  defined,  and  tbe  wood  is  perforated  with  small 
wbidi  MoitAin  WBin  {Fig.  4).    fJompiriid  witVi  wiV  W% 


4  A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

wood  of  these  conifers  is  open-textured  and  soft.  The  difference 
is  so  constant  that  these  trees  are  generally  called  the  soft-wood 
trees  in  contra-distinction  to  hard-wood  trees  such  as  oak,  ash, 
elm,  birch,  beech,  mahogany,  walnut,  etc.  The  soft-wood  trees 
(the  conifers)  are  easily  distinguished  by  their  needle-shaped 
leaves. 

Among  the  hard-wood  trees  the  oak  is  pre-eminent  for  the 
distinctness  of  its  annual  rings.  In  some  others,  e.g.  the  box, 
the  wood  is  so  close  and  compactly  formed  that  the  separate 
rings  are  only  distinguished  with  difficulty.  Such  woods  are 
in  general  heavier  and  more  difficult  to  work  than  soft-woods. 

Felling. — Trees  vary  considerably  in  their  period  of  growth, 
and  if  left  to  grow  after  they  have  attained  maturity  begin  te 
decay.  Although,  strictly  speaking,  this  fact  does  not  directly 
concern  the  carpenter  and  joiner — as  he  generally  purchases  his 
timber  from  the  merchant — it  is  desirable  to  have  some  idea  of 
the  age  at  which  trees  ought  to  be  cut  down  in  order  to  obtain 
the  best  results. 

It  is  generally  considered  that  the  oak  and  most  hard- wood 
trees  are  best  cut  down  at  an  age  of  from  120  to  200  years. 
Soft-wood  trees,  such  as  the  firs  and  pines,  are  ready  for 
felling  after  from  70  to  100  years  growth.  The  proper  time  of 
the  year  to  cut  down  a  tree  is  in  the  early  winter,  when  the 
sap  is  at  rest.  If  the  tree  is  felled  during  the  spring,  summer, 
or  early  autumn,  the  sap  which  is  then  iiowing  will  affect  the 
durability  of  the  wood. 

Converting. — As  an  average  tree  when  cut  down  contains 
from  26  to  40  per  cent,  of  moisture,  it  should  be  at  once  so 
sawn  or  "  converted "  that  the  shrinkage  upon  drying  will  not 
split  the  wood.  If  the  tree  is  left  unsawn  the  outer  layers  dry 
first  and  cause  splitting  to  take  place  in  a  radial  direction. 
The  method  of  converting  depends  upon  the  character  of  the 
wood,  the  purpose  for  which  it  is  to  be  used,  and  possibly  upon 
the  country  from  which  it  is  obtained.  It  must  be  remembered 
that  wood  shrinks  least  in  the  radial  direction,  that  is,  in  a 
direction  at  right  angles  to  the  annual  rings,  therefore  the 
method  of  conversion  will  materially  affect  the  amount  of  shrink- 
age that  takes  place.  It  is  also  of  some  importance  to  know 
that  the  outer,  or  bark,  side  of  a  plank  or  board  will  wear 
better  and  be  less  likely  to  "shell"  than  the  inner,  or  hearty 
aide;  for  example,  the  plank  of  Fig.   14  will  shrink  less  in 


TIMBER,  5 

width  than  that  ot  Fi_'  H,  while  in  Fig.  13  it  wculil  be 
better  to  expoee  the  side  Y  n,thpi  than  the  aide  J'.  In  order 
to  obtain  the  beautiful  marking  known  as  silver  grain  in  oak, 
it  is  neteKsaiy  to  Louveit  the  log  so  that  all  the  saw  cuts 
are  rad'al  ihia  result  la  obtained  by  fiint  cutting  the  tree 
into  quajt«ringa,  Chat  is,  aauing  bj  two  radial  cuts  at  right 
anglea  to  eaih  other,  as  shown  in  Fig  S  This  also  allows  the 
wood  to  shrink  without  the  danger  of  Bjilittiiig.  Other  bard- 
wooda  aie  sometimes  cut  in  a  similar  nianoer. 

Soft  wood  trees  are  generally  cut  into  planks  and  lioarits  of 
marketable  aectioDs  Tlie  exai.t  way  depends  upon  the  size  of 
the  tree,  but  in  all  cases  care  should  lie  taken  not  to  have  the 


pith  in  the  inaide  of  a  plank.  Fig.  6  shows  how  such  trees 
are  usually  cut.  As  most  of  the  timber  used  in  tbia  country  ia 
iraported  from  abroad,  the  question  of  conyersion  seriously 
affecta  the  mode  and  cost  of  conveyance.  It  is  economical 
to  send  across  the  aea  the  better  qualities  of  mat«rial  only, 
moat  compact  form  for  stacking  during 
render  this  possible,  large  saw-niilla 
int  to  the  foreata  where  the  trees  grow. 
:es  are  sawn  into  the  various  mai'ketabie 
1(1  only  the  Ijetter  quality  of  material  is  shipped. 
Baasoning. — As  previously  explained,  a  large  percentage  ot 
moisture  is  present  in  timber  when  the  tree  is  felled.  As  this 
nioistui'e  dries  out,  the  wood  contiaets.  It  ia  therefoi'e  neceasary 
that  the  limber  be  seasoned  by  e&posure  to  the  air  for  sotue  time 
ie  used  satiafaatorily  for  eonstruct\on8.\  'par^Qwa.    i 


and  to  have  these  in  the 
transport.     In  order  tt 

At  these  saw-mills  the  ti 


I 


the  wood  have  alao  a  decided  influence  upon  the  amount  e 
sbrinkage  that  takes  place  during  seaaoning.  Fig.  7  ahows  tl 
efiect  of  leaving  the  trunk  of  a  i 

"     '  h'jw  each  of  t 

planks  into  whifh  a  balk  is  e 
will  be  likelj"  to  be  a  ~ 
Beosoiiing.  Figs.  9  abd  10  si 
respectively  how  a  quarter  i 
jog,  and  a  rectangular  pi 
each  cut  so  that  o. 
tains  the  pith,  will  be  atfec 
by  being  neaeoned. 

The  beat  method  of  aeoaonii 
w'lod  is  to  stack  it  in  such 
"'^-^Tt.Z^uilli^'^^IT'""      "ifti'ner  that  the  air   can 
ciilate    freely    all     round    ■ 
piece.     This  is  done  in  a  variety  of  ways  according  to  the  a 
able  apttMi  in  the  tiuilrer,  or  etorage,  yard.     The  ground  used  fo 
storage  piti'jioaoa  should  lie  dry,  and  fitte  from  grass  o 
vegetation. 

A  shed  with  ojten  sides  and  euds,  wliei*  the  nxif  is  cariied  o" 
pillars,  is  a  particularly  suitable  place  fur  stacking  wood  during 
the  seasoning  procens,  as  the  timber  ia  thus  protected  from  the 


TIMBER. 


direct  rays  of  the  sun  and  also  from  the  min,  wLile  tlie  open 
sides  allow  of  a,  free  circulation  of  air. 

When  spare  is  liinited,  a.  method  of  sMcking  often  resorted 
M,  especially  with  wide  boards,  is  to  arrange  the  hoards  hori- 
zontally over  each  other  with  short  thin  latha,  called  "akida," 
?B  and  between  the  Ixnii'ds.  These  skids  are  placed  iu 
vertical  rows  about  3  feet  apart,  great  care  being  taken  to  have 


them  exactly  over  each  other  to  prevei 
Ijent  by  the  weiglil  of  those  above. 
"  skidding."  Rough  wooden  frames  a 
which  the  planka  and  boards 


■j  the  lower  boards  beinff 
This  method  is  called 
a  often  constructed  into 
edge  at  a  little 


distance  apart ;  or,  where  space  will  allow,  the  boards  c 
arranged  on  end  on  perches — horizontal  limbera,  at  heighta 
t<>  suit  the  length  of  boards,  supported  upon  posts  across 
which  the  upper  ends  of  the  boai'ds  cross  each  other.  The 
object  in  each  case  is  to  expose  as  much  of  the  surface  of  the 
board  as  possible  to  fresh  air,  as  well  as  to  enable  any 
pai-ticular  piece  to  be  withdrawn  easily.  Strips  of  iron  or 
wood  ai'e  often  nailed  across  the  ends  of  wide  boards  to 
prevent  them  from  splitting. 

This  plan  is  known  as  natural  seaBonlncr,  and  although  it 
rcfjuires  a  considerable  time — varying  with  the  thickness  and 
nature  of  the  material^ — it  yields  the  best  results. 

Timber  is  considered  BufRciently  seasoned  for  carpenters' 
work  when  it  has  lost  about  one-fifth  its  weight;  for  Joiners' 
work  a  loss  of  one-third  is  necessary.  Wood  used  for  joiners'  or 
other  linished  woik  is  much  improved  by  a  aecond  saaaoiUiig. 
This  is  effected  by  allowing  the  framing,  or  material,  to  remain 
in  au  unliaished  state  for  Bome  time  before  the  work  is  com- 
^ift^  finally. 


8  A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

Hot-air  Seasoning  or  Desiccating.— Hot-air  seasoniDg  is 
eflfected  by  stacking  the  wood  in  an  artificially  heated  room 
where  the  hot  air  quickly  dries  out  the  moisture.  This  method 
has  an  advantage  over  natural  seasoning  in  that  it  can  be 
completed  in  a  comparatively  short  time.  The  disadvantages 
of  its  use  are : 

(1)  it  can  only  be  satisfactorily  applied  to  small  pieces  ;  if 
used  for  large  pieces  the  heat  dries  the  outside  before  the  inside 
is  aflfected,  and  therefore  tends  to  split  the  wood  ; 

(2)  if  applied  to  newly  sawn  wood  it  is  very  liable  to  cause 
shakes  (cracks)  in  the  wood  ; 

(3)  wood  so  seasoned  is  not  fit  for  outside  work,  as  it  will  be 
aflfected  by  varying  changes  in  the  atmosphere,  absorb  moisture, 
swell  in  damp  weather,  and  contract  in  hot  dry  weather  ; 

(4)  it  reduces  the  strength  of  the  wood  and  also  aflfects  the 
colour  of  some  of  the  better  varieties. 

Water  Seasoning. — The  sap  in  wood  can  quickly  be  got 
rid  of  by  immersing  the  wood  in  a  running  stream  of  water, 
and  afterwards  stacking  it  in  the  air,  where  the  water  which 
has  taken  the  place  of  the  sap  is  easily  dried  out.  The  timber 
being  treated  in  this  manner  should  be  immersed  completely, 
and  should  have  the  end  of  the  wood  to  the  flow,  wich  the 
butt,  or  lower,  end  against  the  stream.  This  process,  like  the 
hot  air  process,  has  the  advantage  of  being  quickly  performed, 
but  it  reduces  the  elasticity  and  durability  of  the  wood,  and 
also  makes  it  brittle. 

Boiling  and  Steaming. — Wood  can  also  be  seasoned  either 
by  immersion  in  boiling  water  or  by  exposure  to  steam.  These 
methods  can  only  be  adopted  on  a  small  scale  owing  to  the 
expense  incurred  in  the  operation. 

The  trouble  and  expense  involved  in  the  seasoning  of  wood 
has  led  to  numerous  experiments  being  performed  with  a  view 
of  changing  the  character  of  the  sap,  so  that  it  is  solidified  and 
rendered  practically  unshrinkable,  while  at  the  same  time  the 
strength  of  the  wood  is  not  affected.  These  have  however, 
as  yet,  not  become  extensively  applied. 

Defects. — The  quality  of  timber  is  seriously  aflfected  by 
accidents  to  the  growing  tree.  These  may  be  caused  by 
lightning,  high  winds,  the  unskilful  lopping  oflf  of  branches, 
etc.  Knots  are  the  bases  of  side  branches  and  may  be  divided 
into  two  classes,  (a)  loose  or  dead  knots,  which  are  the  remains 


TIMBER. 

f  decayed,  or  brolieD,  luanehes,  and  (h)  good,  sound  knots. 
;never  a  knot  occui'a  in  wood,  the  grain  is  theiybj  diverted 
1  the  straight,  and  the  resulting  timber  ia  called  cross- 
'ained.  If  the  knot  is  amall  and  BOiind  it  does  not  affei^t  the 
f  the  material  seiiously  unless  such  is  to  be  used  for 
~  carrying  purposes.  A  super-abundiiuce  of  knots  generally  indi- 
cates that  the  wood  ia  obtained  from  the  upper  end  of  the  tree. 
Knots  cause  estra  labour  in  working,  are    objectionable  ia 

superior  finished  work,  and  are  a  source  of  weakness  in  beams. 

^^t     Heart  shakes  (Fig.  II)  are  defects  that  occur  in  the  growing 
^^Kree  and   are   liable  to  exist   in   almost  every  kind  of   wood. 


star  shakes  are  similar  to  heart   shakes,   and   often   extend 
almost  through  the  tree. 

Cup  shakes  are  those  that  follow  the  path  of  the  annual  rings 
ig.  12).  These  shakes  often  seriously  interfere  witlj  the 
t  of  material  obtainable  from  the  tree  during  the  con- 
1  into  planks  and  boards.  Their  cause  is  attributed  to 
rong  winds  swaying  the  tree,  to  tlie  action  of  excessive  frost 
jistura  present  in  the  tree,  or  to  the  tree  being 
ruck  by  lightning  when  growing, 

bed  flbtas  are  caused  by  a  branch   having   been  cut  off 

i  stump  covered  by  subsequent  growth.     The  result  is 

t  the  fibres  become  diverted  from   the  straight.     Twisted 

s  may  also   be   caused  by   exceptional  storms  and  strong 

is  affecting  trees  in  exposed  situations. 

s  caused  by  a  branch  having  been  torn  off  and  the 
ir  frost,  thus  getting  into  the  tree.  It  ia  indicated  by  a 
it  yeUowUh  stain. 


10        A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

Doatiness  is  a  speckled  staining  found  in  some  kinds  of  hard 
wood. 

Rindgalls  are  caused  by  the  bark,  and  possibly  some  of  the 
fibres  underlying  it,  being  damaged  by  a  blow,  or  by  a  branch 
being  lopped  off. 

Upsets  are  places  where  the  continuity  of  the  fibre  has  been 
interfered  with  by  crushing. 

FozineBs  is  a  disease  affecting  the  timber  through  overgrowth. 
In  this  disease  the  fibres  of  the  wood  assume  a  yellow,  or 
reddish,  colour. 

Wet  Rot  is  a  decomposition  of  the  fibres  of  the  wood  and  may 
take  place  while  the  tree  is  growing.  It  is  induced  by  the  wood 
becoming  thoroughly  saturated  with  water.  It  is  also  often 
found  when  the  timber  has  been  stacked  in  a  damp,  or  wet, 
situation  without  air. 

Dry  Rot  is  one  of  the  most  troublesome  of  timber  diseases. 
It  attacks  unseasoned  timber  in  positions  where  there  is  not 
a  free  access  of  air.  The  disease  is  caused  by  a  fungus-growth 
which  reduces  the  fibres  of  the  wood  to  a  powder.  Dry  rot 
may  be  prevented  almost  entirely  by  taking  care  to  use  only 
thoroughly  seasoned  timber  which  is  entirely  free  from  sap- 
wood,  and  by  providing  for  an  abundance  of  fresh  air,  especially 
at  the  ends.  The  conditions  most  favourable  to  the  growth  of 
dry  rot  are  found  in  the  lower  floors  of  buildings  where  a  warm 
and  moist  atmosphere  exists,  and  where  the  ends  of  joists  are 
built  into  the  walls  in  such  a  manner  that  a  free  circulation  of 
air  cannot  take  place  around  them.  Dry  rot  can  be  recognised 
by  the  white  or  brown  mushroom-like  fungus  which  covers  the 
surface  of  the  attacked  wood.  At  first  such  timber  becomes 
brown  in  colour,  and  brittle  like  charred  wood  ;  at  a  later  stage 
it  falls  to  a  powder.  Dry  rot  spreads  very  rapidly,  and  will 
travel  over  brick  or  stonework,  and  even  affect  plaster.  When 
once  contracted,  this  disease  is  very  difficult  to  exterminate. 

Injury  caused  by  Animals. — Timber  is  very  subject  to 
destruction  by  various  mites,  ants,  etc.,  especially  in  certain 
positions.  They  destroy  it  by  boring  their  way  through  the 
wood.  This  does  not  affect  timber  used  for  carpentry  and 
joinery  to  such  an  extent  as  it  does  that  used  in  shipbuilding, 
dockyard,  and  harbour  construction. 

The  Teredo  navalls,  commonly  called  the  shipworm,  is  a  worm- 
shaped,  greyish-white   mollusc,  often  twelve  inches  long  and 


tiMBER.  11 

half-an-inch  in  diameter,  which  bores  its  way  through  the  wood 
and  thus  destroys  it.  The  ravages  made  by  this  animal  in  many 
dockyards  are  notorious.  It  attacks  most  kinds  of  woods  and 
destroys  them  quickly.  Many  attempts  have  been  made  with 
varying  success  to  prevent  the  depredations  of  these  animals ; 
the  expedients  adopted  include  coating  the  piles  and  other  wood- 
work with  sheet-copper,  driving  flat-headed  nails  close  together 
into  the  timber,  saturating  the  wood  with  creosote,  etc. 

Termites  (white  ants),  and  various  other  organisms  also 
attack  many  kinds  of  wood  and  quickly  destroy  them.  As 
wood  attacked  by  these  animals  is  recognised  easily  by  the 
forester  or  timber  merchant,  it  rarely  comes  under  the  notice 
of  the  wood- worker ;  a  detailed  description  of  the  injury  is 
therefore  unnecessary  here. 

Preservation. — In  order  that  wood  may  be  durable  it  must 
be  perfectly  free  from  sapwood,  shakes,  and  other  defects,  have 
been  properly  seasoned,  and  be  well  ventilated. 

Paint  is  perhaps  one  of  the  best  preservatives  for  finished 
woodwork  that  has  to  be  exposed  to  the  weather,  as  it  not  only 
renders  the  surface  impervious  to  wet  and  other  atmospheric 
influences,  but  also  lends  itself  to  decoration.  For  inside  work, 
painting,  varnishing,  or  polishing  is  resorted  to,  as  much  for 
cleanliness  and  decoration,  as  for  preservation.  For  rough  out- 
side work,  tarring  is  often  adopted,  and  is  a  good  substitute  for 
painting. 

Timber  which  is  buried  in  the  ground — for  example,  posts  for 
hoardings,  rail  fencings,  etc. — may  be  preserved  either  by 
tarring:  or  cliarring  the  surface  of  the  part  that  has  to  be  buried. 

Cliarring  consists  of  burning  the  whole  of  the  outer  surface  so 
that  it  is  covered  with  a  layer  of  charcoal.  The  charcoal  acts  as 
a  preservative  and  protects  the  interior  of  the  timber  from 
parasitic  growths.  It  should,  however,  be  understood  that 
painting,  tarring,  or  charring  will  not  preserve  unseasoned  or 
imperfectly  seasoned  wood.  On  the  contrary,  by  closing  the 
pores  it  may  prevent  the  escape  of  the  sap  from  the  wood,  and 
thus  induce  a  state  favourable  to  decay. 

Creosote  oil,  a  coal  tar  pioduct,  which  is  a  powerful  antiseptic, 
is  perhaps  the  most  extensively  used  of  all  timber  preservatives. 
It  is  forced  into  the  pores  of  the  wood  under  pressure  after  the 
sap  has  been  removed  by  previous  seasoning.  The  process  ia 
hriefiy  aa  follows  :  The  seasoned  timber  is  p\acft^  m  ^  n«to\\^\) 


12        A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

iron  cylinder  connected  with  an  air  pump.  The  air  pump  is 
worked  until  the  pressure  inside  the  cylinder  is  from  one-sixth 
to  one-eighth  that  of  the  outside  air.  By  this  means  the  air 
is  ahnost  entirely  withdrawn  from  the  pores  of  the  wood. 
Creosote  oil,  at  a  temperature  of  about  110"  F.,  is  then  admitted 
into  the  cylinder  and  is  sucked  up  by  the  air-exhausted  pores  of 
the  wood.  After  the  timber  has  taken  up  as  much  oil  as  it  can 
under  these  conditions,  more  creosote  is  forced  into  the  cylinder 
at  a  pressure  of  from  8  to  10  atmospheres.  The  timber  is  thus 
made  to  take  up  more  oil,  and  the  process  is  continued  until  the 
pores  of  the  wood  are  impregnated  thoroughly  with  the  pre- 
servative. In  this  way  some  of  the  softer  woods  may  be  made 
to  absorb  10  lbs.  of  creosote  oil  per  cubic  foot.  Creosote  is  the 
best  known  preservative  against  the  attack  of  destructive 
organisms.  Its  more  general  use  as  a  preservative  is  prevented 
by  the  obnoxious  smell  which  the  timber  permanently  retains. 

Other  preservatives,  which  consist  of  chemicals  dissolved  in 
water,  have  been  used  to  a  limited  extent  for  saturating  the 
timber,  but  have  been  found  either  very  costly,  of  poisonous 
character,  or  liable  to  affect  the  strength  or  colour  of  the 
timber,  and  have  therefore  not  become  adopted  generally. 
Among  these  chemical  methods  are  : 

Kyan'B  process,  which  consists  of  impregnating  the  timber 
with  a  solution  in  which  1  lb.  of  corrosive  sublimate  (bichloride 
of  mercury)  is  dissolved  in  10  gallons  of  water  ; 

Burnett's  process,  in  which  zinc  chloride,  in  the  proportion  of 
1  lb.  to  4  gallons  of  water,  is  forced  by  pressure  into  the  pores 
of  the  wood ; 

Bouclierie's  system,  where  1  lb.  of  copper  sulphate  dissolved  in 
about  12  gallons  of  water  is  used  as  the  preservative,  and  is 
forced  into  the  timber. 

The  I^Gden-Bretenneau  process  of  Electric  seasoning  is  a  recent 
invention  for  seasoning  and  preserving  timber  for  which  nmch 
is  claimed.  It  consists  of  replacing  the  sap  in  the  pores  of  the 
wood  by  solid  matter,  which  is  insoluble  and  aseptic.  The  wood 
is  placed  in  a  vat  containing  the  solution,  and  a  sheet  of  lead 
connected  to  the  positive  pole  of  a  dynamo  is  placed  under  it, 
a  second  sheet  of  lead  connected  to  the  negative  pole  is  placed 
in  a  shallow  wooden  tray  on  the  top  of  the  material  being 
treated.  By  electro-capillary  attraction  the  sap  is  drawn  out 
and  rises  to  the  surface,  being  replaced  by  the  preserving 


TIMHKR. 


Hkea   fi'niii   five   fo  eiglit  Imurs,  after 
goud   woatlier   I'oiiderB  the 


Pwolutioii.  The  piow 
■which  a,  fortnight's 
wood  fit  for  use. 

Qualities  of  Good  Timber.^ From  the  foregoing  conaLdera- 
tiona  it  will  be  seen  thnt  defects  and  disenHOs  are  \evy  prevalent 
in  timber ;  it  must  be  borne  in  mind  also  that  the  quality  and 
durability  depend  largely  iipm  the  nature  of  the  soil  in  which 
the  tree  grows,  the  ti't.atineiit  of  the  tree  during  growth,  the 
method  of  converaion,  the  care  taken  to  effeut  proper  aeaaoning, 
and  the  method  of  preaervation. 

For  conatructional  purposes  wood  should  be  straight-grained, 
free  from  large,  loose,  or  deaci  knots,  and  from  Kajjwood.  The 
k^nnual  rings  should  be  oi  even  thickneas  ;  the  cloaer  they  are 
^ther  the  stronger  is  the  timber ; 
Ind  as  a  rule  the  darker  the  colour 
naturally-coloured  woods,  the 
er.  The  timlier  should  be 
nreet-sraelling,  and  when  planed 
X  should  have  a  firm,  bright,  silky  j 
lustre.  A  disagreeable  smell,  a 
woolly  surface,  or  a  chalky  appear- 
ance, indicates  decay.  The  timber 
should   be   a    good    conductor   of 

sound  and,  however  long  the  piece,        pjg  jj^  P,j  i^ 

the    ticking   of   a    watch,    or    the 

scratching  of  one  end,  should  be  distinctly  heard  by  anyone 
"'  tening  at  the  other  end.  When  used  for  framing,  less  danger 
C  shrinkage,  and  better  results  in  other  reapecta,  are  obtained. 
Kall  the  pieces  are  cut  ao  that  their  width  is  perpendicular  to 
e  annual  rings,  with  the  heart  edge  inwards.  When  possible 
KiBecond  seasoning  after  framing  before  finally  finiahing  olF  the 

ork  should  take  place. 

ft  Tor  caiTying  purposes,  a  beam  which  has  the  annual  rings 

"ben  in  position  (Fig.   13)  is  stronger  than  when  the 

pual  rings  are  horizontal  as  shown  in  Fig.  14,  in  the  propoi- 

n  of  about  8  to  7.     Floor  boards  shrink  less  and  wear  longer 

n  cut  with  the  annual  rings  at  right  anglea  to  the  exposed 

a  ;   if  they  are  to  be  cut  with  the  rings  parallel   to  the 

B  they  ahould,  to  prevent  shelling,  have  the  heart  aide 

Q  when  placed  in  poaition. 

Varieties  o/Tuuber.— Most  of  the  timber  used \iil'teKCfi<m\.CT 


14         A   MANUAL  OF  CARPENTRY   AND  JOINERY. 

iH  imported.  Ah  previously  mentioned,  it  is  classed  as  "soft- 
wood" and  "  hanl-w(MKl."  For  carpentei's'  and  joiners'  work  the 
soft-woods  are  extensively  iwed,  both  on  account  of  their  abund- 
ance, their  small  cost  as  compared  with  many  hard-woods,  and 
the  ease  with  which  they  can  be  worked.  Hard- woods  are, 
however,  employed  where  strength  is  necessary,  or  where  a 
superior  finisli  is  d(}siral)le.  The  soft-woods  in  most  general 
use  are  red  deal,  white  deaU  yellow  pine^  and  pitch  pine. 

Bed  Deal,  Yellow  Deal,  Bed  or  Yellow  Fir,  Northern 
Pine,  and  Scotch  Fir  are  diftei-ent  names  given  to  the  wood 
obtained  from  the  same  species  of  tree  (Pinus  sylvestris).  As 
a  very  large  quantity  of  this  timber  is  exported  from  the  ports 
on  the  Biiltic  Sea  it  is  often  described  as  Baltic  fir.  It  is  the 
product  of  one  of  the  conifers  which  flourishes  best  in  exposed 
mountainous  districts  in  a  dry  sandy  soil.  The  annual  rings  are 
very  distinctly  marked,  and  vary  in  thickness  from  \  ^  ^  oi 
an  inch.  The  wood  varies  considerably  both  in  texture  and 
appearance,  the  closer-grained  wood  being  very  even  and  of  a 
yellowish  colour,  while  the  more  quickly  grown  timber,  with 
coarse  annual  rings,  yields  a  wood  which  is  rich  in  resin  and  of  a 
reddish  colour.  This  resinous  character  renders  it  very  durable, 
especially  for  outside  work.  The  sap-wood,  which  varies  much 
in  quantity,  is  of  a  bluish-colour ;  while  the  knots  are  of  a 
hard  transparent  nature. 

Red  Deal  is  one  of  the  strongest  and  most  durable  of  soft- 
woods, the  best  qualities  compai'ing  favourably  with  many 
hard-woods.  It  is  one  of  the  most  extensively  used  of  soft- 
woods for  outside  work,  beams  for  carrying  purposes,  floor 
and  roof  timbers,  etc.,  and  weighs  when  dry  from  32  to  35  lbs. 
per  cub.  foot. 

It  grows  in  abundance  in  Russia,  l*russia,  Norway,  Sweden, 
and  Scotland.  The  best  qualities  are  obtained  from  St.  Petera- 
burg,  Onega,  Dantzic,  Archangel,  Gefle,  and  Soderhamm. 

White  Deal  or  Spruce  is  the  wood  of  the  spruce  fir  (Picea 
excelsa).  In  appearance  it  is  of  a  brownish- white  colour,  with 
annual  rings  fairly  distinct.  It  is  inferior  in  strength  to  red 
deal.  It  is  more  liable  to  shrink  and  warp  during  seasoning, 
and  the  poorer  qualities  contain  hard  glassy  knots  which 
increase  the  difficulty  of  working  it.  The  sapwood  is  scarcely 
distinguishable  from  the  heartwood.  It  is  used  for  scaffold 
poles  and  planks  for  temporary  constructional  work,  and  being 


TIMBER.  15 

cheap  as  compared  with  most  other  woods,  it  is  used  in  many 
parts  of  the  country  for  such  work  in  buildings  as  floor  joists, 
roof  timbers,  floor  boards,  etc.  It  is  also  in  much  demand 
for  packing  cases,  telegraph  poles,  fencing,  etc.  It  weighs  from 
30  to  36  lbs.  per  cub.  foot  when  dry. 

It  is  obtained  from  Russia,  Norway,  Sweden,  and  North 
America.  The  best  qualities  are  shipped  from  Onega,  St. 
Petersburg,  Riga,  and  Christiania. 

Yellow  Pine  {Pinus  strohiis)  is  an  American  timber.  It  is 
known  in  America  as  the  white  pine.  It  is  very  soft,  of 
uniform  texture,  of  a  honey-yellow,  or  straw,  colour,  and  is 
easily  worked.  The  annual  rings  are  not  so  distinct  as  those 
of  the  red  or  white  deal,  and  the  sapwood  is  distinguished  easily 
by  its  bluish  colour.  The  wood  is  fairly  durable  in  dry  situa- 
tions, but  very  liable  to  dry  rot  when  used  in  damp  un ventilated 
positions.  It  is  used  extensively  for  internal  joiners'- work,  for 
pattern-making,  and  by  the  cabinet-maker  for  the  cheaper  kinds 
of  furniture. 

Yellow  pine  is  not  so  strong  as  red  deal,  nor  does  it  warp  like 
white  deal.  Its  weight  when  dry  is  from  24  to  28  lbs.  per  cub. 
foot.  It  grows  in  North  America  and  in  Canada.  Some  of  the 
best  yellow  pine  is  shipped  at  Quebec. 

Pitch  Pine  is  a  heavy  resinous  timber  which  grows  in  the 
Southern  part  of  North  America.  There  are  several  trees  the 
wood  of  which  receives  this  name,  among  which  are  the  long- 
leafed  pine  {P.  palustris  or  P.  Au8tralis\  the  short-leaved  pine 
{P.  echinata  or  P,  mitts),  the  loblolly  pine  (P,  taeda)  and  the 
Cuban  pine  (P.  Cvherms).  Although  each  of  these  trees  diflfers 
in  some  of  its  characteristics  from  the  others,  the  wood  from 
them  is  scarcely  distinguishable,  and  the  result  is  that  it  is  mixed 
indiscriminately,  and  classed  in  this  country  as  pitch  pine. 

Pitch  pine  is  noted  for  its  straight  grain,  freedom  from  large 
loose  knots,  and  for  the  large  amount  of  resin  it  contains.  It 
may  be  described  as  of  resinous  appearance.  The  annual  rings 
are  very  distinct  and  regular,  while  the  sap-wood,  being  of  a 
bluish  colour,  is  easily  distinguishable  from  the  heart-wood. 

Pitch  pine  is  chiefly  imported. into  this  country  in  the  balk, 
and  being  obtainable  in  large  sizes— up  to  70  feet  in  length  and 
20  inches  square  in  section — it  is  in  much  demand  for  heavy 
beams  for  engineering  structures,  heavy  scaffolding,  gantries., 
shoring  and  abruttiDg,  for  roof  tiusses,  wooden  girdera,  ^ii^ XXi'^ 


16        A  MANUAL  OF  CARPENTRY  AND  JOINERY.     ' 

heavy  beams  of  carpenters'  work  generally.  It  is  also  used  for 
the  finished  woodwork  of  such  public  buildings  as  schools, 
churches,  etc.,  where  the  resinous  appearance  and  grain  of  the 
wood  lend  themselves  to  varnishing  instead  of  painting.  Some 
of  the  trees  yield  a  wood  that  has  a  wavy,  or  curly,  grain.  This 
wood,  which  has  a  beautiful  appearance,  is  much  sought  after 
for  panels  and  other  decorative  work. 

Pitch  pine  weighs  from  38  to  44  lbs.  per  cub.  foot  when 
dry.  The  chief  ports  from  which  it  is  shipped  are  Pensacola, 
Savannah,  and  Darien. 

Canadian  Bed  Pine  is  the  product  of  a  tree  (Pinus  resinosa) 
which  grows  in  North  America  and  Canada.  In  appearance 
this  wood  is  similar  to  the  lighter  kinds  of  pitch  pine,  and  is 
often  substituted  for  it.  It  compares  favourably  with  red  deal, 
the  best  quality  being  very  clean  and  free  from  defects.  It  is 
not  in  great  demand  in  this  country. 

Oregon  Pine,  known  as  the  Douglas  pine,  is  the  product  of 
one  of  the  largest  of  the  American  pines,  or,  to  be  more  correct, 
fir  trees  {Pseudotsuga  Bouglasii),  It  is  found  in  the  Western 
part  of  N.  America.  This  wood  is  of  a  reddish-white  colour, 
fairly  strong,  straight  grained,  of  quick  growth,  and  can  be 
obtained  of  very  large  size.  It  is  sometimes  used  as  a  substitute 
for  red  deal  or  yellow  pine  in  buildings. 

Sequoia  or  Califomian  Bedwood  is  an  American  timber 
obtained  from  a  tree  {Sequoia  sempervirens)  which  often  grows  to 
a  height  of  400  feet,  and  a  diameter  varying  from  12  to  30  feet. 
The  wood  is  of  a  dark  brownish-red  colour,  with  coarse  annual 
rings,  and  is  liable  to  be  brittle  and  lacking  in  strength.  It  is 
obtainable  in  very  large  pieces,  but  is  not  much  used  in  the 
construction  of  buildings. 

Larch  {Larix  Europaea)  is  a  native  of  the  European  Alps,  and 
also  grows  abundantly  in  Russia  and  Siberia.  It  is  a  light, 
tough,  coarse-grained  wood  (Fig.  3),  red  or  yellowish-white 
in  colour,  and  has  an  excessive  tendency  to  shrink  and  warp. 
Its  coarse  grain  and  warping  tendencies  prevent  its  general 
use  for  finished  work  of  importance.  It  can  be  used  with 
advantage  for  scaffolding  poles,  rough  boarding,  piles,  etc. 

Hard  Woods.  Oak. — Many  different  varieties  of  oak  grow 
both  in  this  and  in  other  countries.  Querents  rohur  pedunculata 
(the  common  oak)  and  Qiierctis  rohur  sesdliflora  are  the  two 
varieties  most  common  in  the  British  Isles. 


TIMBER.  17 

British  oak  is  regarded  as  ime  of  the  strongest  and  most 
durable  of  woods.  It  ia  generally  taken  as  the  standal'd  when 
comparisona  are  made  with  other  woods.  It  is  tough,  hcu'd, 
strong  and  ver;  elastic,  the  grain  is  of  even  texture,  and  it 
contiiiiiB  a  powerful  acid  which  rapidly  corrodes  iron  fast«iiingfl, 
and  leaveH  a  blue  stain  iu  the  wood.  Britiuh  oak  is  of  a  light- 
brown  colour,  and  when  cut  in  a  plane  pei'pendicular  to  the 
annual  rings  shows  silvery  patches  (silver  giuin). 

It  ia  used  for  all  kinds  of  engineering  structurea,  by  ship- 
builders, wheelwrights,  coach-builders  and  coopers;  cabinet- 
makers consider  it  one  of  their  most  valuable  woods,  while  the 
builder  uses  it  where  great  strength  and  durability  are  requii-ed, 
as  well  as  in  important  buildings  for  decoiative  work,  where 
advantage  ia  taken  of  the  beautiful  marking  of  the  silver  grain. 
American  oak,  many  varieties  of  which  eiist,  is  not  so  strong, 
nor  ao  hard  as  the  British  oak.  It  baa  a  coai'se  grain,  ia  of  a 
reddiah-brown  colour,  and  is  much  used  as  a  substitute  for 
British  oak. 

The  oak  also  grows  in  Bussia,  Norway,  and  other  European 
eountriea,  and  ia  imported  into  this  country  in  the  log  or  balk. 
Each  kind  has  its  peculiar  chaiacteriatic,  distinguishable  only 
by  the  expert,  and  as  the  supply  of  British  oak  ia  not  equal  to 
the  demand,  foreign  oak,  being  more  plentiful  and  consequently 
often  substituted.  Oak  weighs  from  45  to  60  Iba. 
cub.  foot  when  dry. 
Teak  {Tectona  grandis)  is  found  in  Clentral  and  Southern 
India.  It  is  a  heavy,  atrong,  straight- grained  wood  conlaining 
an  aromatic  reainoua  oil  which  tenda  to  preserve  iron  fastenings 
and  also  acts  aa  a  preservative  against  worms,  ants,  etc.  It  ia 
a  very  durable  wood,  of  a  greenish -brown  colour,  not  so  liable 
to  shrink  and  warp  as  some  woods,  and  is  suitable  for  use  in 
floors  which  are  subject  to  heavy  traffic,  in  treads  of  stairs, 
wooden  silla,  and  where  great  strength  ia  required.  It  ia  railcll 
used  by  the  ship-builder  and  for  railway  atock. 

ly   (Mahogaiii  mmeUnia)   is   obtained  from   Central 
and   from   t.Hiba,   and   other  West   Indian    Islands, 
lOgany  may  be  divided  into  two  classes  : 

1)  Bpaniah,   or   Cuba,  Hahosany  ia   hard,   compact,    of   even 

reddish-brown  colour,  with  chalk-like  lines  showing 

surface.     It  often  abows  a  lieautifully  marked  grain,  it  ia 

ible  to  twis^  ami  is  capable  of  being  wrought  to  aYvj 


the  (I 

mi 


18        A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

finished  surface  which  polishes  readily,  and  thus  shows  the 
grain  to  great  advantage. 

This  wood  is  used  for  the  best  class  of  superior  joiners'-work, 
hand-rails  for  staircases,. etc.,  and  is  also  much  in  demand  by 
the  cabinet-maker. 

(2)  Honduras  or  Bay  Mahogany,  obtained  from  Central  America, 
has  some  of  the  characteristics  of  the  former  variety.  It  is, 
however,  much  softer,  more  easily  worked,  and  is  not  so  rich  in 
colour,  nor  does  it  possess  the  beautiful  grain  of  Spanish 
mahogany.  It  is  much  used  as  a  cheaper  substitute  for  that 
wood. 

Walnut  (Juglaiis  regia)  grows  in  Southern  Europe,  in  Asia, 
America,  and  also  in  this  country.  It  is  a  hard  wood,  brown  in 
colour,  close  grained,  has  a  beautiful  figure,  and  when  wrought 
will  take  a  fine  polish.  The  best  kind  comes  from  Italy.  It 
is  used  in  superior  joiners'-work  and  also  for  furniture. 

Many  other  kinds  of  timber  are  used  to  a  limited  extent  for 
special  purposes  by  the  carpenter  and  joiner.  A  detailed 
description  of  these  is  beyond  the  scope  of  this  book.  The 
following,  however,  call  for  casual  reference  : 

Ash  is  a  light-coloured  wood  with  annual  rings  very  distinct, 
and  is  noted  for  its  elasticity  and  its  toughness.  It  is  used  by 
the  coachbuilder,  the  wheelwright,  the  cabinet  maker,  and  for 
agricultural  implements. 

Beech  is  of  hard,  even  grain,  of  a  reddish  colour,  and  is  used 
for  furniture,  wood-turning,  and  by  wood-working  toolmakers. 

Birch  is  very  hard,  liable  to  excessive  shrinkage  and  warping, 
it  makes  good  flooring  for  heavy  wear,  and  is  much  used  by  the 
cabinet-maker  and  wood-turner. 

Chestnut  being  of  a  brownish  colour  resembles  oak,  excepting 
that  it  has  no  visible  medullary  rays.  It  is  used  for  piles,  and 
occasionally  as  a  substitute  for  oak. 

Elm  is  a  coarse-grained  wood  which  is  very  durable  in  damp 
situations. 

Maple  has  a  clean,  white,  satin-like  appearance,  with  a  hard 
close  grain  which  is  not  liable  to  splinter.  It  is  a  very  suitable 
wood  for  superior  flooring. 

Sycamore,  which  is  allied  to  the  maple,  has  a  close  compact 
grain,  with  a  clean  appearance,  and  is  used  by  the  wood-turner 
for  domestic  requirements,  and  also  in  the  fittings  of  butchers' 
shops  by  reason  of  its  clean  appearance. 


TIMBER.  19 

The  ash,  beech,  birch,  chestnut,  elm,  maple  and  sycamore  are 
all  trees  that  grow  in  a  temperate  climate,  and  are  consequently 
found  in  this  country,  most  European  countries,  and  in  America. 

Canary  Wood. — There  are  two  or  three  kinds  of  wood  which 
are  indiscriminately  mixed  and  known  as  canary  wood  : 
American  white  wood,  bass  wood,  and  tulip- tree  wood.  All 
kinds  grow  in  America,  are  of  a  light  yellowish-green  colour, 
not  very  hard,  easily  worked,  and  can  be  obtained  in  large  size. 
Canary  wood  is  often  used  for  panels,  and  also  for  furniture. 

Greenheart  is  obtained  from  South  Aiuerica  and  the  West 
Indies.  It  is  of  dark  greenish  colour,  heavy,  even-grained,  and 
of  oily  nature.  It  is  used  for  heavy  engineering  work,  piles, 
dock  gates,  bridge  construction,  etc. 

Jarrah  wood  is  obtained  from  Western  Australia,  and  has  a 
reddish-brown  appearance  very  much  like  mahogany.  Being  a 
very  hard,  close-grained  wood,  it  is  used  for  heavy  engineering 
work,  for  piles,  for  street  paving,  and  the  best  qualities  for 
furniture. 

Rosewood  is  obtained  from  Southern  India  and  Brazil.  It  is 
of  a  rich  dark  colour,  hard  and  even  texture,  and  possesses  a 
beautiful  grain.  It  is  capable  of  a  high  pulish,  and  is  used  by 
the  cabinet-maker  and  occasionally  for  superior  joiners'- work 

Summary. 

Trees  used  for  timber  arc  classified  as  : 

(a)  Hard  wood,  e.g.  oak,  ash,  beech,  birch,  mahogany,  walnut, 

etc. ;  usually  have  broad  leaves  ;  non-resinous. 
(h)  Soft  wood,  e.g.  red  de^l,  white  deal,  yellow  pine,  pitch  pine, 
etc. ;  markedly  resinous  ;  leaves  needle  shaped. 
The  wood  of  timber  consists  of  concentric  bands  called  annual 
rings  :  each  ring  represents  a  year's  growth. 

The  medullary  rays  are  radial  strips  of  tissue  reaching  from  the 
pith  to  the  bark.     In  some  trees  they  are  not  easily  seen. 

Trees  should  be  cut  down  ii>  the  early  winter,  and  should  be  so 
converted  into  quartering  or  planks  that  the  shrinkage  during 
seasoning  will  he  uniform. 

Seasoning  is  the  process  of  drying  to  which  wood  is  subjected  to 
make  it  fit  for  use.  The  commonest  methods  are  "natural  "  season- 
ing and  hot-air  seasoning. 

The  principal  defects  of  tiniber  arc  due  to  mechanical  shakes,  various 
diseases  set  up  by  fungi,  and  injury  by  insects  and  otWex  9u&ra\8X%. 


20        A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

Timber  is  preserved  by  painting,  charring,  and  various  methods 
of  chemical  treatment. 

Qood  timber  is  free  from  disease,  shakes,  dead  knots,  and  sap- 
wood,  and  should  be  straight  grained.  The  smell  and  the  power  of 
conducting  sound  are  valuable  tests.  The  suitability  for  various 
purposes  is  affected  by  the  manner  of  sawing  the  log. 

Most  of  the  timber  used  in  this  country  is  Imported. 

The  soft  woods  most  commonly  used  are  obtained  from  the  pines 
and  firs,  amongst  which  are  red  or  yellow  deal,  white  deal  or  spruce, 
yellow  pine,  and  pitch  pine. 

The  hard  woods  used  include  oak,  teak,  mahogany,  walnut,  ash, 
beech,  birch,  elm,  sycamore,  etc. 

Questions  on  Chapter  I. 

1.  Describe  the  method  of  growth  of  the  wood  of  some  common 
tree.     What  is  the  cause  of  the  formation  of  annual  rings  ? 

2.  Draw  a  cross  section  through  the  trunk  of  an  oak  tree,  about 
40  years  old,  naming  the  various  parts  shown.  Describe  the 
appearance  of  a  radial  longitudinal  section  of  the  same  tree  trunk, 
and  explain  the  cause  of  the  marking  known  as  "  silver  grain." 

3.  What  is  the  difference  between  heartwood  and  sapwood?  How 
is  the  difference  produced,  and  how  does  it  affect  the  value  of  the  wood? 

4.  At  what  time  of  the  year  is  it  best  to  cut  down  trees,  and 
why  ?  What  is  meant  by  "  converting,"  what  is  its  object,  and  how 
is  it  carried  out  in  (a)  oak  ;  (b)  white  deal  ? 

5.  Why  should  timber  be  seasoned  ?  What  effect  has  Masoning 
upon  its  weight  and  size  ?  What  will  be  the  result  if  unseasoned 
timber  is  used  in  (a)  carpenters' ;  (h)  joiners'  work  ? 

6.  Describe  the  chief  methods  of  seasoning  timber,  and  compare 
their  advantages. 

7.  What  are  the  chief  defects  to  be  found  in  timber,  and  how  are 
they  produced  ? 

8.  Describe  the  difference  between  dry  rot  and  wet  rot.  State 
how  these  diseases  originate,  and  how  they  may  best  be  combated. 

9.  Describe  the  various  methods  of  preserving  timber. 

10.  Enumerate  the  chief  points  to  be  looked  for  in  the  selection  of 
timber  of  good  quality.  % 

11.  Give  a  descriptieh  of  the  following  soft  woods :  white  deal,  red 
or  yellow  deal,  yellow  pine,  pitch  pine.  State  the  distinguishing 
features  of  each,  the  chief  sources  of  supply,  and  the  purposes  for 
which  each  is  most  suitable. 

12.  Describe  the  principal  varieties  of  hard  wood,  and  state  for 
what  purposes  each  kind  is  specially  suitable. 


CHAPTER  II. 

PLANE  GEOMETBT. 

A  STUDENT  can  neither  prepare  nor  properly  understand  the 
working  drawings  necessary  before  the  varied  work  of  Carpentry 
and  Joinery  can  be  successfully  undertaken,  unless  he  has  some 
preliminary  knowledge  of  Practical  Geometry.  As  it  is  unlikely 
that  this  preliminary  knowledge  is  possessed  by  all  readers  of 
this  book,  it  will  be  necessary  at  the  outset  to  deal  briefly  with 
some  of  the  more  essential  principles  of  the  subject. 

The  student  is,  however,  strongly  recommended  to  make  a 
systematic  study  of  Practical,  Plane,  and  Solid  Geometry,  as  the 
space  here  available  is  insufficient  for  more  than  a  consideration 
of  a  few  fundamental  principles. 

Drawing  Instmments. — The  student  will  require  a  drawing- 
board.  Tee-square,  set  squares,  dividers,  compasses,  pencils, 
india-rubber,  etc.  For  ordinary  class  work  the  drawing-board 
(preferably  of  yellow  pine)  may  conveniently  be  23"  long  and 
16"  wide.  It  will  then  be  suitable  for  use  with  half  an  imperial 
sheet  of  drawing  paper.  The  Tee-square,  which  may  have  either 
a  tapering  or  parallel  blade,  should  be  slightly  longer  than  the 
board.  To  allow  the  set  square  to  slide  over  the  stock  of  the 
Tee-square,  it  is  better  to  have  the  blade  screwed  on  to  the 
stock  rather  than  let  in  flush.  Two  set  squares,  one  with 
angles  of  90,  60,  and  30  degrees,  and  the  other  with  angles 
of  9u,  45,  and  45  degrees  are  required.  These  may  be  of  hard- 
wood, but  are  better  of  celluloid.  The  accuracy  and  ease  with 
which  drawings  can  be  made  depends  largely  upon  the  quality 
of  the  instruments  used.  Inexperienced  students  would  do 
well,  therefore,  to  seek  advice  before  purchasing  such  instru- 
ments as  compasses,  dividers,  etc.,  as  many  cheap  Vixx^  ^Tao«Xi 


22       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


Chiselpoint. 


'sy 


worthless  sets  are  put  upon  the  market.     HB  pencils  are  used 
for  taking  notes,  but  harder  pencils  are  necessary  for  drawing ; 

H  or  HH  are  the  most 
suitable.  Cheap  pencils 
of  poor  quality  should 
not  be  used.  The  method 
of  sharpening  pencils  de- 
serves attention.  Figs. 
15  and  16  show  a  pencil 
sharpened  with  a  chisel 
point.  A  point  formed 
in  this  manner  will  last 
longer,  when  used  for 
drawing, than  the  rounded 
pencil -point  shown  in 
Fig.  17. 
FiQ.  15.  Fio.  16.  Fig.  17.       Measurement      of 

Length. — In  this  country 
linear  measurements  are  usually  made  in  yards,  feet,"  inches, 
and  fractions  of  an  inch.  The  usual  sub-divisions  of  the  inch 
are  eighths,  tenths,  and  twelfths.  The  sub-divisions  of  the 
inch  generally  employed  by  carpenters  and  joiners  are  powers 
of  two,  giving  ^",  J",  \'\  etc.  In  geometry,  however,  the  sub- 
divisions are  often  given  in  decimals,  and  the  inch  is  then 
divided  into  tenths. 

In  many  continental  countries  the  metric  system  is  adopted. 
The  unit  of  measurement  in  the  metric  system  is  the  metre, 
equal  to  39*37  English  inches.  This  is  divided  into  10  deci- 
metres ;  the  decimetre  is  divided  into  10  centimetres  ;  and  the 
centimetre  is  divided  into  10  millimetres. 

Measurement  of  Angles.— Definition.  An  a7igle  is  the  incli- 
'nation  of  two  lines  which  meet  at  a  'point  in  a  plane.  An  angle 
may,  in  familiar  language,  be  said  to  be  "  the  size  of  the  corner." 
It  ought  to  be  noticed  that  an  angle  does  not  in  any  sense 
depend  on  the  length  of  the  lines  "containing"  it.  If  two  lines 
AB  and  CB  meet  at  the  point  B  (Fig.  18)  the  angle  contained  by 
AB  and  CB  is  referred  to  as  "  the  angle  A BC^^  If  two  straight 
lines  be  drawn  to  cross  each  other  so  that  the  four  resulting 
angles  are  equal  (Fig.  19),  the  lines  are  said  to  be  perpendicular^ 

^  In  ordinary  work  it  will  generally  be  found  convenient  to  draw  perpen- 
dicular lines  with  the  aid  of  Tee  and  set  squares. 


PLANE  GEOMETRY. 


23 


to  each  other  and  the  angles  are  right  angles.     A  right  angle  is 
divided  into  90  equal  parts  which  are  called  degrees  (written  °). 


9or 


Right 
angle 


Fig.  18. 


Fio.  19. 


It  follows  that  the  sum  of  all  angles  which  meet  at  a  point  in  a 
plane  {i.e.  in  a  flat  surface)  is  4  x  90°  =  360°. 

Several  methods  are  adopted  for  measuring  angles,  but  possibly 
the  easiest  and  the  most  common  is  by  means  of  the  protractor. 


O30k     «s   M  WToloiaiOTW  »  40      JO^ 


^0 

11 1  ml  I  Ml  I  iiiitiinl 


2e^ 

10-- 


»i  iilii  111  mil  iliiliiir 


""Imiliiiilmi 


Fig.  20. 


Fig.  20  shows  a  rectangular  protractor  with  the  main  divisions 
indicated  thereon. 


PBELIMINABT  DEFINITIONS. 

Paxallel  lines  are  everywhere  the  same  distance  apart,  and 
therefore  never  meet  however  far  they  are  produced. 

An  acute  angle  is  one  which  is 
smaller  than  a  right  angle  (Fig.  18). 

An  obtuse  angle  is  one  that  is 
greater  than  a  right  angle  (Fig.  21). 

A  circle  is  a  plane  figure  contained  \  Obtuse  angle 

by  one  curved  line  which   is   called 
the  drcuinference ;  the  line  is  such  Fio.  21. 


24       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

that  all  points  in  it  are  equidistant  from  a  point  within  the 
circle  called  the  centre  (Fig.  22). 

The  radios  of  a  circle  is  a  straight  line  drawn  from  the 
centre  to  the  circumference.     It  follows  from  the  definition 


xunfcrcnce 


Pia.  23. 


Segment  oPa  circle 


Fia.  22. 


Chord 

Fig.  24. 


of    the   circle    that   all    radii   of    the   same    circle   are   equal 
in  length. 

A  diameter  of  a  circle  is  a  straight  line  passing  through 
the  centre  and  terminated  at  both  ends  by  the  circumference : 
it  is  equal  in  length  to  twice  the  radius. 


Fig.  25. 


FiQ.  26. 


An  arc  of  a  circle  is  part  of  the  circumference  of  a  circle 
(Fig.  23). 

A  chord  is  a  straight  line  joining  any  two  points  in  the  circum- 
ference of  a  circle  (Fig.  24). 

A  segment  (Fig.  24)  is  a  portion  of  a  circle  contained  by  any 
arc  and  the  chord  between  the  extremities  of  the  arc.  If  the 
chord  is  a  diameter  the  arc  is  half  the  circumference,  and  the 
segment  is  called  a  semicircle  (Fig.  25). 


PRELIMINARY  DEFINITIONS. 


25 


A  sector  is  a  portion  of  a  circle  contained  by  any  two  radii 
and  the  arc  between  their  outer  ends  (Fig.  26). 

A  tan^rent  is  a  straight  line  touching, 
but  not  cutting,  the  circumference  of 
a  circle  (Fig.  22).  It  is  always  at  right 
angles  to  the  radius  drawn  to  the  point 
of  contact. 

Concentric  circles  are  circles  having 
the  same  centre  (Fig.  27).  Their  cir- 
cumferences are  therefore  parallel  to 
each  other.  The  periphery  of  a  circle 
is  the  length  of  the  circumference.  Fkj.  27 


SIMPLE  EXERCISES  INVOLVING  THE  USE  OF 
STRAIGHT  LINE,  ANGLES,  AND  CIRCLES. 

Example  1. — To  bisect  a  given  straight  line,  i.e.  to  divide  it 
into  two  equal  jparts. 

Let  AB  (Fig.  28)  be  the  given  straight  line.     Take  a  pair  of 
compasses  and  with  centre  A  {i.e.  placing  the  steel  point  on  the 

point  A)  and  radius  greater 
than     one    half    AB    {i.e. 
1?  separating   the  legs  of  the 

compasses   to   any  distance 
greater    than    one    half  of 

^D    AB)    draw    the    arc    CD, 

With  the  same  radius  (that 
is,  keeping  the  compasses 
open  to  the  same  extent) 
and  with  centre  B,  draw 
Q'    r  the  arc  ^i^  intersecting  the 

Pjq  28.  *^^  ^^  ^^  *'^®  points  G  and 

H.  Join  GH  {i.e.  draw  a 
straight  line  from  G  to  H).  The  point  AT  where  the  line  Gllcuts 
AB  bisects  AB  {i.e.  divides  it  into  two  equal  parts).  The  line 
Gff  is  perpendicular  to  the  line  A  B,  that  is  at  right  angles  to  it. 

Example  2. — To  divide  a  given  straight  line  into  any  number 
Of  equal  parts  {say  5). 

Take  any  straight  line  A  B  (Fig.  29)  ;  from  A  draw  a  second 
straight  line  AC,  of  indefinite  length,  making  an  acute  angle 


A 


26         A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


with  AB.     Along  AC  mark  off  5  equal  parts  and  number  them. 

Join  the  point  5  to  the  point  B,  and  through  the  points  1,  2,  3,4, 

—by  means  of  the  set 
squares — draw  lines  par- 
allel to  bB.  These  parallel 
lines  divide  AB  into  the 
required  number  (6)  of 
equal  parts.  The  divisions 
of  the  inclined  line  should 
be  such  that  the  parallel 
lines  are  nearly  at  right 
angles  to  the  given  line. 

Example    3. — To   draw 
a  circle   which   shall  pau 
throitgh  three  given  points  not  in  the  same  straight  line. 

Let  A,  B  and  C  (Fig.  30)  be  the  given  points.    Join  AB  and 
BC,     Bisect  AB  and   BC  as  in  Example  1  by  straight  lines 


Fio.  29. 


Fki.  30. 


at  right  angles  to  AB  and  BC  respectively.  Tlie  point  of 
intersection,  0,  of  the  bisectors  is  the  centre  of  the  recjuired 
circle. 

ExAMi'LK  4. —  To  bisect  a  given  angle. 

Let  ABC  (Fig.  31)  be  the  given  angle.     With  B  as  centre 
and  any  radius  descril>e  an  arc  cutting  BA  and  BC  in  the  points 


SIMPLE  EXERCISES. 


27 


D  and  E  respectively.     With  centres  D  and  E  and  any — the 

same — radius,  describe  arcs  intersecting  at  G.    The  straight  line 

BG    bisects    the    angle 

ABC,   the    angle   ABG 

being  equal  to  the  angle 

CBG. 

Example  5.—  To  draw 
a  petyendicvlar  to  a 
given  straight  Une^from 
a  given  point  in  the  line. 

Let  AB  (Fig.  32)  be 
the  given  line  and  C 
the  given  point.  With 
centre  C  and  any  radius 
describe  arcs  intersect- 
ing AB  m  D  and  E,  With  D  and  E  respectively  as  centres 
and  any  radius  greater  than  CD  draw  area  intersecting  at  F, 
The  straight  line  FC  is  perpendicular  to  AB. 


>CC 


>CF 


E^B 


S3 


/^ 


XF 


FiQ.  82. 


Pio.  88. 


Example  6. —  To  draw  a  perpendicular  to  a  given  straight  line, 
from  a-  given  point  outside  the  line. 

Let  A  B  (Fig.  33)  be  the  given  straight  line  and  C  the  given 
point.  With  centre  C  and  any  radius  greater  than  the  perpen- 
dicular distance  from  C  to  JZ?,  draw  the  arcs  intersecting  AB 
at  D  and  E.  With  D  and  /s  as  centres,  and  with  any — the  same 
— radius  draw  arcs  intersecting  at  F.  The  straight  line  CF  \a 
'p^vpendicular  to  AB. 


28        A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


TRIANGLES. 

A  triangle  is  a  plane  figure  having  three  sides.  Triangles  are 
named  according  to  their  shape.  The  sum  of  the  angles  in  any 
triangle  is  alwajB  equal  to  two  right  angles  (ISO**).  A  triangle 
may  therefore  have  three  acute  angles  (Fig.  34),  but  it  can  only 


Equilateral 

Fio.  84. 


Isosceles 

Fig.  35. 


Right  Angled 

Fio.  36. 


contain  one  right  angle,  or  one  obtuse  angle  (as  an  obtuse 
angle  is  greater  than  a  right  angle).  An  equilateral  triangle  is 
one  that  has  all  its  sides  of  equal  length,  and  all  its  angles  equaL 


Obtuse  Angled 

Pio.  87. 

An  isosceles  triangle  is  one  that  has  two  sides  of  equal  length. 
A  scalene  triangle  has  three  sides  of  unequal  length. 
Figs.  34  to  38  show  these  diflferent  kinds  of  triangles  with  the 
name  of  each  appended. 

Example  1. — To  construct  an  equilateral  triangle  of  given  side. 

Let  AB  (Fig.  39)  be  the  given 
side.  With  A  as  centre  and  AB  as 
radius  draw  an  arc  of  a  circle.  With 
B  as  centre  and  the  same  radius  draw 
a  second  arc  intersecting  the  first  at 
C.  Join  A  C  and  BO.  ABC  is  the 
required  triangle.  It  will  be  found 
by  measurement  that  each  angle  of 
Fio.  89.  an  equilateral  triangle  equals  60**. 


TRIANGLES. 


29 


Example  2. — To  construct  a  triangle  whose  sides  are  in  the 
proportion  of  3,  4,  5. 

Let  the  line  AB  (Fig.  40)  have  a  length  of  3  +  4  +  5  =  12 
units.  Divide  ABin  the  required  proportions  as  shown.  With 
C  as  centre  and  radius  equal  to  CA  (3  units)  draw  the  arc  AE. 


y 


■         ■         ■         ' 


B 


Pro.  40. 


With  D  as  centre  and  DB  (5  units)  as  radius,  draw  BE  inter- 
secting AE  at  E.  Join  CE  and  DE.  CDE  is  the  required 
triangle. 

The  solution  of  many  examples  in  the  construction  of  tri- 
angles is  simplified  by  a  knowledge  of  the  fact  that  all  the 


Pio.  41. 


Fio.  42. 


amgles  opposite  the  chord  of  the  same  segment  of  a  circle  are  of 
eqtud  mxignitvde.  For  example,  in  a  semicircle  (Fig.  41)  the 
angle  contained  by  any  two  lines  drawn  from  A  and  B  to  any 
point  in  the  arc  is  a  right  angle.  When  the  segment  is  smaller 
than  a  semicircle  (Fig.  42),  all  the  angles  contained  by  any 
two  lines  drawn  from  the  extremities  of  the  chord  to  any  point 
in  the  arc  are  obtiise  angles  (a,  a),  and  are  of  equal  magnitude. 
If  the  BegmeDt  is  greater  than  a  semicircle,  ti\[ie  Sk.^^.-vv.Ti^'^ 


30 


A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


(the  one  opposite  the  chord)  is  an  acute  angle  (Fig.  43,  a,  a,  a), 
all  the  angles  of  the  same  segment  being  equal. 


Fig.  48. 


Fio.  44. 


Example  3. —  7b  construct  a  right-angled  isosceles  triangle 
halving  a  given  length,  of  hypotenuse  {the  side  opposite  the  right 
angle). 

Let  AB  (Fig.  44)  be  the  given  hypotenuse.  On  the  line  AB 
construct  a  semicircle.  Then  the  angle  contained  by  any  two 
lines  drawn  from  A  and  5  to  a  point  in  this  semicircle  will  be  a 
right  angle.  As  an  isosceles  triangle  is  in  this  case  required,  it 
will  be  necessary  to  erect  a  perpendicular  line  passing  through 
the  centre  C  of  the  semicircle  and  intersecting  the  arc  at  D. 
Join  DA  and  DB.  A  DB  is  the  required  triangle,  for  AD  is 
equal  to  BD  and  the  angle  A  DB  is  in  a  semicircle  and  therefore 
equals  90  degrees. 

Example  4. — On  a  given  base  to  construct  an  isosceles  triangle 
having  a  vertical  angle  of  70**. 

Let  AB  (Fig  45)  be  the  given  base.     Draw  CD  perpendicular 

to  and  bisecting  AB.  From  A 
draw  a  line  making  with  AB 
an  angle  of  90°  minus  the  apex 
angle— i.e.  90° -70"  =  20°.  The 
intersection  of  this  line  with  CD 
gives  the  centre  0.  With  OA  as 
radius  complete  the  segment  of 
the  circle.  Join  AD  and  BD. 
ABD  is  the  required  triangle. 

Example    5. — To    construct   a 
triangle   co7itaining  an  angle  of 
110°  and  having  its  two  longer  sides  in  the  proportion  of  4  and  3. 
First,  determine   the  segment   of  a  circle  which  will  con- 
tain   an  angle  of  110°.      Let   AB   (Fig.  46)  be  the  longest 


TRIANGLES. 


31 


side  of  the  triangle.  From  A  di-aw  AO  (below  AB)  making 
an  angle  with  AB  oi  11 0**  -  90"  =  20*  (the  difference  between 
the  required  angle  and  a 
right  angle).  The  centre  0 
of  the  segment  is  the  point 
where  this  line  intersects 
the  bisector  CD  of  the  line 
AB.  Then  any  two  lines 
drawn  from  A  and  B  to  any 
point  in  the  arc  will  con- 
tain the  required  angle  110% 
Next  divide  AB  into  4  equal 
parts.  With  A  as  centre  and  ^3  as  radius  draw  the  inter- 
secting arc  3E.  Join  AE  and  BE.  ABE  is  the  required 
triangle,  since  ^4^  is  to  AB  as  3  is  to  4,  and  the  angle  AEB 
equals  110°. 

Example  6. — At  a  given  point  in  a  given  straight  line,  to  draw 
an  angle  equal  to  a  given  angle. 

Let  MON  (Fig.  47)  be  the  given  angle,  and  A  the  given 
point  on  the  line  AB.    On  AB  with  A  as  centre  make  AG  equal 


FiQ.  4(5. 


Fm.  47. 


to  OM.  With  A  as  centre  and  ON  SiS  radius  draw  an  arc  B. 
With  G  as  centre  and  radius  MJV  draw  the  arc  intersecting  at 
D.  Join  AD.  Then  the  angle  GAD  is  equal  to  MON  and  is 
therefore  the  required  angle. 


32        A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

Example  7. — Given  an  arc  of  a  circle,  the  centre  of  which  is 
inaccesdhley  to  continue  the  curve. 

Take  any  three  points  A,  B,  (7,  in  the  given  arc  and  join  AB, 
BC.    From  any  point  A'  draw  the  chord  A'B'  equal  to  AB  and 


Fio.  48. 


from  B'  draw  B'C  such  that  the  angle  A' BO  is  equal  to  the 
angle  ABC  and  BC  equal  to  BC.  C  is  a  further  point  in  the 
curve.  Obtain  other  points  in  the  same  manner  and  join  them 
by  an  even  curve. 


QUADKILATEKAL  FIGURES. 

A  quadrilateral  figure  is  one  which  is  contained  by  four 
straight  lines.  The  straight  lines  joining  opposite  angles  of  a 
quadrilateral  figure  are  called  diagonals.  Figs.  49  to  64  show 
different  quadrilateral  figures  with  their  names  appended. 


Square 

Fio.  49. 


Rectangle 

Fio.  60. 


Rhombus 

Pio.  51. 


The  sum  of  the  angles  of  any  quadrilateral  figure  is  always 
equal  to  four  right  angles. 

A  paralieiograxn  is  a  quadrilateral  figure  which  has  two 
pairs  of  parallel  sides. 

A  rectangular  figure  is  one  having  all  its  angles  right  angles. 
The  two  diagonals  of  any  rectangular  figure  are  always  equal  in 
length. 


QUADRILATERAL  FIGURES.  ^ 

A  square  (Fig.  49)  has  all  its  sides  of  equal  length  and  all  its 
angles  equal  (right  angles). 

A  rectangle  or  oblone:  (Fig.  60)  has  the  opposite  sides  of 
equal  length,  and  contains  four  right  angles. 

A  rhombus  (Fig.  51)  has  all  the  sides  of  equal  length,  but 
the  angles  are  not  right  angles.  It  may  be  described  familiarly 
8.8  a  square  pushed  out  of  shape. 


Rhomboid  Trape|oid  Trapezium 

Fio.  52.  Fio.  53.  Fio.  54. 

A  rhomboid  (Fig.  52)  has  the  opposite  sides  of  equal  length 
but  its  angles  are  not  right  angles. 

A  trapezoid  (Fig.  53)  has  two  sides  parallel  but  of  different 
lengths. 

A  trapezium  (Fig.  54)  has  none  of  its  sides  parallel. 

In  all  quadrilateral  figures  except  the  square  and  the 
rectangle  it  is  necessary  to  know  either  the  lengths  of  the 
diagonals,  or  the  magnitudes  of  the  angles,  in  addition  to 
the  lengths  of  the  sides,  before  the  figure  can  be  constructed. 

POLYGONS. 

A  polygon  is  the  name  given  to  any  plane  figure  which  is 
bounded  by  straight  lines.  Usually  the  name  is  not  applied  to 
triangles  and  quadrilateral  figures,  but  only  to  figures  bounded 
by  more  than  four  straight  lines. 

A  regrular  polygron  has  all  its  sides  of  equal  length  and  its 
angles  are  of  equal  magnitude. 

If  the  sides  are  not  equal  the  polygon  is  said  to  be  irregnilar. 

Polygons  are  named  according  to  the  number  of  their  sides, 

as  pentagon  (5  sides),  hexagon  (6  sides),  heptagon  (7  sides), 

octagon  (8  sides),  nonagon  (9  sides),  decagon  (10  sides),  un- 

decagon  (11  sidesi  duo-decagon  (12  sides),  etc. 
jcaj,  c 


34 


A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


Via.  55. 


Example  1. — To  construct  a  regrdar  hexagon  of  given  side. 

Let  AB  (Fig.  55)  l)e  the  length  of  the  given  side.     On  AB 
construct  an   equilateral   triangle  AOB.      With  centre  O  and. 

radius  OA  draw  a  circle 
passing  through  A  and  B, 
With  the  same  radius  and 
starting  from  A,  mark  inter- 
secting arcs  on  the  cir- 
cumference of  this  circle. 
It  will  be  found  that  six 
6(1  ual  lengths  are  thus 
obtained.  By  joining  these 
points  by  straight  lines,  the 
re(][uired  hexagon  is  com- 
pleted. The  angle  between 
any  two  sides  of  a  regular 
hexagon  measures  120*. 
This  figure  can  also  be 
drawn  easily  with  the  aid  of  the  60"  set  square. 

Example   2. — To  construct  a  regular  pentagon  of  given  side, 

{First  method.)  Let  ^5  (Fig.  56)  be  the  length  of  the  required 
side.  Produce  AB  to  C.  With  A  as  centre  and  AB dis  radius 
draw  a  semicircle.  Di- 
vide this  semicircle  (by 
trial)  into  5  equal  parts. 
Through  the  point  2 
(always  point  2,  what- 
ever the  number  of  sides 
of  the  polygon)  draw  the 
straight  line  '2, A .  Bisect 
2A  and  AB  by  lines 
at  right  angles  to  them. 
The  point  0  where  these 
bisecting  lines  meet  is 
the  centre  of  the  circle 
which  will  contain  the 
required  figure.  Start- 
ing from  A  with  radius 

AB,  mark  of!'  lengths  on  the  circumference  of  the  circle.     Join 
the  points  By  C,  Z),  2,  .4.    Then  ABCD2  is  the  required  pentagon. 


Fio.  50. 


rOLYGONS. 


35 


Fio.  57. 


If  any  other  regular  polygon  is  required,  the  same  construction 
is  applicable  ;  care  must  l>e  taken  to  divide  the  semicircle  into 
as  many  equal  parts  as  the  number  of  sides  of  the  required 
polygon,  and  to  work  from  the  second  division. 

{Secoiid  method.)  Let  AB  (Fig.  57)  be  the  given  side.  On 
AB  construct  the  square  ABCDkixA  also  the  equilateral  triangle 
ABQ,  Draw  the  diagonals  of  the 
square.  These  intersect  at  4,  the 
centre  of  a  circle  which,  if  drawn 
with  4.A  as  radius,  will  pass  through 
the  angles  of  the  square  ABCD. 
The  point  6  is  the  centre  of  a  circle 
which  with  QA  as  radius  will  con- 
tain a  six-sided  figure  (Ex.  1).  By 
bisecting  the  distance  between  6 
and  4  a  point  5  is  obtained,  which 
is  the  centre  of  the  circle  containing 
the  required  pentagon.  With  centre 
5  and  radius  bA  draw  the   circle 

passing  through  A  and  B,  Take  AB  as  radius,  and  with  A  as 
starting  point  "stride"  round  the  circumference  of  the  circle. 
By  joining  the  points  5,  E,  F^  Gy  A,  the  required  pentagon  is 
obtained.  This  method  is  applicable  to  the  construction  of  any 
polygon.  If  a  heptagon  is  required,  a  distance  6,  7  equal  to  5,  6 
is  measured  above  the  point  6  as  shown.     The  point  7  is  the 

centre  of  a  circle  which  with 
radius  lA  will  contain  a  regular 
heptagon,  as  shown  in  dotted  lines 
in  Fig.  57. 

An  octagon  can  be  easily  drawn 
with  the  aid  of  the  45°  set  square 
as  shown  in  Fig.  58. 

Any    regular    polygon    can    be 

drawn  by  directly  measuring,  with 

the  protractor,  the  angles  between 

the  sides.     The  angle  required  in 

each  case  is  obtained  by  reasoning 

as  follows  :  Every  regular  polygon 

consists  of  a  number  of  equal  isosceles  triangles.     The  sum  of 

the  angles   of  a  triangle   is   equal    to    180".      If  a  heptagon 

(Fig.  59)  is  required,   the   apex   an^j^les  of   7    equaX  Vao^ct^Vi^ 


Fio.  58. 


36        A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

triangles  meet  at  the  centre  of  the  figure.     As  the  sum  of  the 
angles  between  all  the  lines  drawn  through  a  point  equals  360', 

the  apex-angle  of  each  of  these 
triangles  equals  s^<^  =  51  f°. 
Each  of  the  other  two  angles 
of  each  triangle  is  therefore 


equal  to 


180* 


-5iy^ 


2 


64?'.  As 


two  of  these  are  at  the  angle 
between  any  two  sides  of  a 
heptagon,  then  64f  x  2= 128f 
is  the  required  angle. 

Similarly  the  apex  angle  for 
a  pentagon  is  *jfi=72*.  The 
base  angle  of  each  isosceles 

triangle  is ^ =54  ,  and 

therefore  the  angle  between 
Fio.  59.  any  two  sides  of  the  pentagon 

is  54"  X  2=108". 
For  an  octagon  the  apex  angle  of  each  of  the  eight  triangles 
composing  it  is  *^|fi  =  45°.     The  base  angle  of  each  of  these 

triangles  is =67^" :   therefore  the  angle  between  any 

two  sides  is  67 J"  x  2  =  135". 

For  the  construction  of  irregular  polygons,  the  lengths  of 
the  sides,  and  either  the  lengths  of  the  diagonals  or  the  magni- 
tude of  the  various  angles  are  required. 


mSCBIBED  AND  CIBCXJMSCBIBED  FIQUBES. 

An  inscribed  figure  is  one  that  is  contained  by  a  larger 
figure,  and — if  an  angular  one — has  its  sides  terminated  by  the 
sides  or  the  circumference  of  the  larger  or  circumscribing  figure. 
If  the  inscribed  figure  is  a  circle,  the  sides  of  the  circumscribing 
figure  are  tangents  to  the  circle.  Thus,  a  circle  which  is  con- 
tained by  a  triangle  and  touches  each  side  of  the  triangle  is 
named  the  inscribed  circle,  while  a  circle  drawn  to  pass 
through  the  three  angular  points  of  the  triangle  is  the  circum- 
scribing circle  of  the  triangle. 


INSCRIBED  AND  CIRCUMSCRIBED  FIGURES.        37 


Example  1. — In  a  given  triangle  to  draw  the  inscribed  circle 
(i.e.  to  draw  a  circle  which 
shall  touch  each  side  of  the 
triangle). 

Let  ABC  (Fig.  60)  be 
the  given  triangle.  Bisect 
any  two  of  the  angles  as 
ABCsindBAC.  The  point 
0  where  these  bisecting 
lines  intersect  is  the  centre 
of  the  required  circle. 
With  0  as  centre,  and 
radius  equal  to  the  per- 
pendicular distance  to  any 
side  of  the  triangle,  draw 
the  circle.  This  is  the 
inscribed  circle  required. 

Example  2. —  About  a 
given  triangle  to  draw  the 
circumscrihitig  circle. 

Let   ABC  (Fig.    61)    be    the    given    triangle.     Bisect   any 
two    sides  AB  and  AC  hy  lines    at    right   angles  to  them. 


Fio.  60. 


>-^. 


Pio.  61. 


The  point  0  where  these  two  intersectoi-s  meet  is  the 
required  centre,  and  is  equidistant  from  the  points  A,  B 
and  C.  With  0  as  centre,  and  OA  as  radius,  draw  the 
required  circle. 


38        A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

Example  3.  —Li  a  given  square  to  ylace  foxir  equal  circles  each 
touching  two  sides  of  the  square  and  two  other  circles. 

Let  A  BCD  (Fig.  62)  be  the  given  square.     Bisect  the  sides 
of  the  square  in  the  points  A*,  F,  Q,  II  and  join  EG  and  FH, 


t 


x^ — . 


-X 


Fio.  62. 


Draw  the  diagonals  of  each  of  these  smaller  squares.  The 
intersections  of  the  diagonals  give  the  centres  of  the  I'equired 
circles  as  shown  in  the  figure. 

Example  4. — In  a  given  square  to  place  four  equal  circles,  each 
touching  one  side  of  the  square  and  two  circles. 

Let  A  BCD  (Fig.  63)  be  the  given  square.  Draw  the  diagonals 
AC  and  BD  intersecting  in  0,  In  each  of  the  four  triangles 
thus  obtained  place  the  inscribed  ciicle  as  in  Example  ]. 

Example  5. — In  a  regular  hexagon  to  place  six  equal  circles, 
each  touching  two  sides  of  the  hexagon  and  two  other  circles. 

Let  ABCDEF  (Fig.  64)  be  the  given  hexagon.  Bisect  the 
sides  of  the  figure  in  the  points  1,  2,  3,  4,  6,  6.     Join  1  to  4,  2 


INSCRIBED  AND  CIRCUMSCRIBED  FIGURES. 


39 


to  5,  3  to  6.     In  the  quadrilateral  figure  IA20,  bisect  any  two 
angles  as  shown.     The  intersection  M  of  these  bisecting  lines 


FiQ.  63. 


gives  the  centre  of  one  of  the  required  circles.     In  each  of  the 
six  quadrilateral  figures  place  a  similar  circle. 


-  '^ 


Example  6. — In  a  given  triangle  to  draw  the  inscribed  sqnare. 
Let  A  BC  (Fig.  65)  be  the  given  triangle.     From  C  draw  CD 
perpendicular  to  ^^.     Draw  CE  parallel  to  AB  and  equal  to 


40        A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


CT>.  Join  AE^  intersecting  BC  at  F.  Draw  FQ  parallel  to 
AB^  and  OH  and  FJ  perpendicular  Xjo  AB,  FGHJ  is  the 
required  square. 


Example  7. — In  a  regular  hexagon  to  draw  the  inscribed  square. 

Let  ABCDEF  (Fig.  66)  be  the  given  hexagon.  Join  AD  and 
draw  GH  perpendicular  to  and  bisecting  AD,  Through  0  draw 
straight  lines  bisecting  the  right  angles  thus  obtained.  The 
points  where  these  lines  intersect  the  sides  of  the  hexagon  as 
JT,  Z,  My  N  are  the  angular  points  of  the  square. 

Example  8. — In  a  given  circle  to  place  two  given  smaller  unequal 
circles  which  touch  each  other 
and  the  given  circle. 

Let  A  (Fig.  67)  be  the 
centre  and  AB  the  radius 
of  the  given  circle.  Draw 
the  diameter  BC.  On  BC 
make  BD  equal  to  the 
radius  of  one  of  the  small 
circles.  With  D  as  centre, 
and  DB  as  radius,  draw 
this  circle.  On  CB  make 
CE  equal  to  the  radius 
of  the  second  small  circle. 
From  centre  A  with  radius 
AE  draw  an  arc.  With  the  same  radius  measure  off  from  F  on 
BC  the  distance  FQ.  With  D  as  centre,  and  DQ  as  radius,  draw 
the  intersecting  arc  QH.  Then  H  is  the  required  centre  of 
the  second  circle. 


Pio.  67. 


PROPORTION. 


41 


PROPORTION. 

Definitions. — If  one  quantity  bears  to  a  second  quantity  the 
relation  which  a  third  bears  to  a  fourth,  the  four  quantities  are 
said  to  be  in  proportion ;  thus  2  bears  to  3  the  same  relation  which 
4  does  to  6 ;  and  2,  3,  4,  and  6  are  said  to  be  in  proportion,  a 
statement  which  is  expressed  thus  2  :  3  : :  4  :  6.  The  same  fact 
may  be  expressed  as  2  : 4  : :  3  :  6  and  as  6  :  4  : :  3  : 2  etc.  In  the 
proportion  2  :  3  : :  4  :  6,  6  is  said  to  be  the  fourth  proportional  of 
2,  3,  and  4.  In  general  terms,  ii  A  :  B  ::  B  :C,  then  B  is  said  to 
be  the  mean  proportional  of  A  and  (7,  and  C  is  the  third  propor- 
tional of  A  and  B.  If  A  :B  ::  C  :  D  then  AxD=BxC.  Simi- 
larly a  A:B::B:C  then  AxC=BxB.  The  product  of  the 
first  and  fourth  quantities  of  a  proportional  is  always  equal  to 
the  product  of  the  second  and  third. 


PiO.  68 

Example  1. — To  determine  the  fourth  proportional  to  three  given 
straight  lines. 

This  problem  depends  upon  the  arrangement  of  the  propor- 
tion. Let  A,  By  and  C  be  the  given  lines  and  let  the  proportion 
he  A  :  B  ::  C:  X,  X  being  the  straight  line  required..  Draw  two 
straight  lines  (Fig.  68)  containing 
an  acute  angle,  as  at  0.  On  ON 
measure  OA'  equal  to  ^,  and  OC 
equal  to  (7,  and  on  OM  measure  o 
OB'  equal  to  B.  Join  A'B'  and 
through  C  draw  C'X  parallel  to 
A'R.  Then  OX  is  the  fourth 
•proportional  required. 

It  C  :B  ::  A  :  X  then  the  result 
will  be  quite  different.     This  is  shown  in  Fig.  69. 
represents  the  fourth  proportional  to  (7,  B,  and  A. 


Fio.  69. 


Here  OX 


42        A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


Fio.  70. 


Example  2. — To  determine  a  third  proportional  to  two  given 
straight  lines. 

Let  A  and  B  be  the  given  lines,  and  let  the  proportion  be 

A  :  B  ::  B  :X,  Draw  the 
Bi..M  two  lines  OM  and  ON 
meeting  at  an  acute  angle. 
On  OM  measure  OA'  equal 
to  J,  and  OB^  equal  to  B. 
On  ON  measure  OB'  also 
equal  to  B.  Join  A'B' 
and  through  B^  draw  B^X 
parallel  to  A'B\  Then 
OX  is  the  required  third 
proportional. 

Example  3. — To  find  a  mean  proportioned  to  two  given  straight 
lines. 

Let  i4  and  5  (Fig.  71)  be 
the  given  lines.  Di-aw  a 
straight  line  and  measure 
upon  it  OA'  equal  to  A, 
and  OB'  equal  to  B, 
Bisect  A'B'  at  C.  With 
C  as  centre,  and  (7/1'  as 
radius,  construct  a  semi- 
circle. From  0  erect  a 
perpendicular  to  A'B' 
cutting  the  semicircle  at 
X,  Then  OX  is  the  mean 
proportional  requiied. 


B. — 


Pia.  71. 


SCALES. 

As  very  few  details  in  working  drawings  can  be  made  of  full 
size,  some  definite  scale  must  be  adopted  to  show  the  necessary 
proportions.  The  scale  used  varies  according  to  the  nature  of 
the  di'awing,  as  well  as  to  the  country  in  which  the  work  is  done. 
Thus,  the  drawings  required  to  illustrate  a  complete  building 
are  made  to  a  small  scale,  usually  one- eighth  of  an  inch  to  the 
foot  in  this  country  ;  while  the  constructional  details  require  to 
be  shown  to  a  much  lai'ger  scale.    Graduated  rules  of  boxwood, 


SCALES. 


43 


or  paper,  may  be  obtained,  on  which  are  marked  scales  of  J,  |, 
S>  h  h  ^»  ^h  ^»  ®^^-  inches  to  the  foot.  Although  these  scales 
are  sufficient  for  ordinary  use,  it  is  occasionally  necessary  to  use 
other  scales,  and  the  student  must  know  how  to  construct  these 
for  himself. 

Example  1. — To  cotistract  a  scale  of  one-seventh  the  full  size,  to 
read  to  feet  and  inches. 

Draw  a  straight  line  AC  (Fig.  72)  and  mark  ofi  AB  one  inch 
long.     From  A  draw  ^^  at  any  angle  (preferably  about  SO**). 


Scafo  ot  one -seventh,  (jj 


Fio.  72. 


On  AE  mark  off  any  12  equal  divisions,  and  number  them. 
Join  the  seventh  point  to  B,  and  through  each  of  the  other 
points  on  ^^draw  lines  parallel  to  B7,  and  cutting  AC.  The 
length  AB  (1")  is  thus  divided  into  seven  equal  parts,  each 
measuring  one-seventh  of  an  inch.  As  the  scale  is  one-seventh 
full  size,  each  division  represents  one  inch,  and  the  distance  AF 
(twelve  divisions)  represents  one  foot.  Mark  the  point  F  zero, 
and  number  the  scale  as  shown.  Then  XV,  e.g.  represents  a 
distance  of  1'  4". 

Example  2. — To  constritct  a  scale  of  one-thirtieth  full  size,  so 
that  one  inch  represents  two  feet  si.v  inches. 

On  AC  (Fig.  73)  make  AB  equal  to  one  inch,  and  on  AE 
mark  off  ten  equal  parts.  Join  the  tenth  point  to  B,  and 
through  the  other  points  on  il^draw  lines  parallel  to  i^lO,  and 
cutting  AB  as  shown.  Then  each  of  the  smaller  divisions  on 
AB  is  one-tenth  of  an  inch  long,  and  therefore  represents  three 
inches.    Mark  the  fourth  division  from  A  zero,  and  WMTC^iev  ^^a 


44        A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

shown  in  Fig.  73.     AF  represents  one  foot,  and  AB  two  feet 
six  inches. 

Satfe  of  One  thirtieth  (ii,) 


I 


£ 


\7f«et 


Fio.  73. 

Example  3. — To  convert  an  English  scale  ofZ  inches  to  the  foot 
into  a  scale  n'pon  the  Metric  system, 

A  scale  of  3  inches  to  the  foot  is  one-fourth  full  size.  By 
dividing  the  length  of  a  decimetre  into  four  equal  parts  it  will 
be  found  that  each  of  the  divisions  is  one-fourth  of  a  decimetre, 
or  a  decimetre  to  a  scale  of  one-fourth  full  size.  Bj  again 
dividing  each  of  these  divisions  into  ten  equal  parts  a  scale 
is  obtained  of  metric  measurements  to  one-fourth  full  size,  Le. 
in  the  proportion  of  3  inches  to  the  foot. 

Example  4. — A  French  working  drawing  represents  one  metre 
by  a  length  of  40  millimetres.  Convert  this  into  an  English  scale 
showing  feet  and  inches. 

40  millimetres  represent  one  metre.  As  there  are  1000 
millimetres  in   a   metre    the  representative  fraction  will    be 


4feefc 


Fia.  74. 


\o%^  —  ^E'  "^^^^  scale  is  therefore  -}g  full  size.  By  drawing  a 
scale  in  which  one  inch  represents  25  inches  (Fig.  74)  the 
required  scale  is  obtained. 

Diagonal  Scales. — These  are  used  when  very  minute  divi- 
sions are  required.     When  constructing  a  scale  to  represent  ^^ 


bi>tli  difficult  and  unsatiafactory  to3 
100  equal  parts  in  the  manner 

2lni!hes 


already  shown.  Fig.  75  ehowa  how  such  a  diagonal  scale  ie 
constructed.  Ten  horizontal  lines,  parallel  to  the  given  lines, 
are  first  drawn,  at  any — the  eamo^ distance  apart,  and  vertical 
lines  erected  which  divide  these  into  one  inch  divisions.  The 
length  of  one  inch  is  then  divided  into  10  equal  parts.  By 
drawing  the  slanting  Hnea  as  shown  in  Fig.  75,  a  scale  is  obtained, 
from  which  any  dimension  to  the  second  decimal  place  of  an 
inch  can  be  measured. 

ExdMFLB  5, — To  cojialmct  a  scale  of  o 
inchei,  and  eighths  of  an  inek. 

The  scale  of  one-ninth  is  first  drawn  with  the  division 
inches  at  the  left-hand  side.     Eight  additional  horizontal  lio 


intk,  to  r 


i  feet. 


will  be  required  in  this  example,  as  the  inches  have  to  he 
divided  into  eighths.  By  drawing  the  slanting  lines  as  shown 
in  Fig.  76  and  numbering,  the  scale  is  corapletad. 


46        A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

Enlarging  and  Diminishing  Figures.— Figs.  77  to  80  are 
examples  which  show  how  siiuilar  figures  in  definite  proportion 
to  each  other  may  be  drawn  easily.  Fig.  77  shows  two  similar 
triangles  ABC  a.i\d  AEC\  the  lengths  of  the  sides  of  which  are 
in  the  proportion  of  2  and  1.  By  bisecting  ABvaE^  and  draw- 
ing EC'  parallel  to  BC^  the  line  JC  is  bisected  in  C^  and  EO  is 
one  half  the  length  of  EC. 

B*. ,€■ 


Fio.  77. 


Pro.  78. 


Fig.  78  shows  how,  by  a  similar  method,  a  small  irregular 
figure  may  be  enlarged  in  any  desired  proportion.  It  is  required 
to  draw  a  figure  similar  to  A  BCDE^  the  sides  of  which  are  to 


N 
N 


>^~V2'l{'-,4.' 


N       N 
N      S 


^--,- 


^"3-; 


Fia.  79. 


the  corresponding  sides  of  A  BCDE  as  3  is  to  2.  AB^  AC^  AD^ 
AE  are  produced.  AE  is  made  one  and  a  half  times  AB,  and 
the  figure  is  completed  by  drawing  parallels, 


ENLARGING    AND   DIMINIBHINO   FIGURIS. 


In  Fig.  79,  which  in  the  section  of  a  common  form  of  mould- 
ing, vertical  and  horizontal  lines  1,  2,  3,  and  1',  2',  3',  a,re  first 
drawn.  Radiating  dotted  lines  are  then  drawn,  from  the  points 
in  which  these  ordinates  intersect  the  straight  sides  of  the 


monjding,  to  a  convenient  point  outside  the  figure.  The  pro- 
portion required  is  nieaaured  on  one  of  these  lines,  and  the 
diminished  or  enlaiged  figure  is  then  obtained  hy  di'awing  lines 
which  intersect  the  radiating  lines,  and  are  parallel  to  corre- 
sponding lines  of  the  given  figure.  Fig.  80  shows  a  somewhat 
more  complicated  moulding  drawn  out  in  a  similar  manner. 


QneBtions  on  Chaptet  IL 

1.  In  mensuring  the  angle  of  a  building,  lengths  of  7  ft.  and  fi  ft. 
respcotivoly  aro  measured  along  the  walls  from  the  oomer;  the 
distance  between  the  two  points  obtained  is  9  ft.  What  is  tho 
iiiclLiiatioN  (in  degror's)  of  tbo  walla  to  eaoh  other! 

2.  A  segmental  arch  over  an  opening  5  ft.  wide  has  a  rifio  in  thu 
middle  of  1  ft.  3  in.     Dotermino  the  radivis  of  tlie  curve. 

3.  The  two  parallel  walls  of  a  building  14  ft.  wide  (outside 
measurement)  have  a  difFeroncc  in  height  of  6  ft.  What  U  tAvfi 
length  of  tho  oommoa  rafters  r^uirod  for  the  rooil 


48        A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

4.  Construct  a  square  having  a  diagonal  4  in.  long. 

5.  Construct  a  regular  pentagon  of  1  '25  in.  aide. 

6.  Construct  an  octagon  within  a  square  of  2  in.  side.  Construct 
a  heptagon  of  1  in.  edge.     (C.  and  G.  Prel.  1900.) 

7.  Determine  the  length  of  the  side  of  a  square  inscribed  in  a 
circle  2*i5  in.  in  diameter. 

8.  Draw  the  circumscribing  circle  about  a  rectangle  having  a 
diagonal  3  in.  long,  and  one  side  1*25  in.  long. 

9.  An  arch  with  a  rise  of  3  in.  and  4  ft.  span  is  the  segment  of  a 
circle.  Show  the  method  of  obtaining  this  curve  without  using  the 
centre  of  the  circle.     (C.  and  G.  Prel.  1904.) 

10.  .Draw  a  triangle  the  sides  of  which  are  in  the  proportion  of 
3,  4,  and  6,  the  perimeter  being  7  in.  Draw  the  inscribed  and 
circumscribing  circles. 

11.  About  a  circle  1*2  in.  radius,  draw  a  triangle  the  sides  of 
which  are  in  the  ratio  of  3,  4,  and  5. 

12.  Describe  the  method  of  inscribing  in  a  circle  any  regular 
polygon.  On  a  given  line  2  inches  long  construct  a  pentagon. 
(C.  andG.  Prel.  1898.) 

13.  Within  a  circle  of  1  in.  radius  construct  a  regular  pentagon. 
(C.  andG.  Prel.  1901.) 

14.  Find  graphically  a  number  which  bears  the  same  proportion 
to  8  which  5  bears  to  4 ;  also  a  number  which  bears  the  same  pro- 
portion to  13  that  13  does  to  9. 

15.  Two  upright  posts  16  ft.  apart,  fixed  on  a  level  site,  are 
respectively  10  ft.  and  5  ft.  high.  Determine  graphically  the  length 
of  two  other  posts  placed  between  these  at  4  ft.  and  9  ft.  distances 
respectively  from  the  shorter  post,  so  that  the  upper  ends  of  all  the 
posts  are  in  line. 

16.  Make  a  plane  scale  to  read  2J  in.  to  1  ft. ,  not  less  than  3  ft. 
to  be  shown.     (C.  and  G.  Prel.  1903.) 

17.  Construct  a  plain  scale  of  IJ  in.  to  1  ft.,  long  enough  to 
measure  4  ft.     (C.  and  G.  Prel.  1904.) 

18.  Construct  a  diagonal  scale  of  ^V  ^^^  size  to  read  feet,  inches, 
and  eighths  of  an  inch. 

19.  Copy  Fig.  78,  A'B'G'D'E'y  p.  46,  to  the  size  given,  and  con- 
struct a  similar  figure,  the  sides  of  which  are  1  '75  times  the  size  of 
those  given. 

20.  Copy,  to  the  same  size,  the  section  of  moulding  given  in 
Fig.  80,  p.  47.  Draw  a  similar  section  to  one  and  a  half  times  the 
size. 


CHAPTER  III. 
SOLID  aEOMETBY. 

Methods  of  Projection.— It  is  ditticult  to  represent,  or 
project,  on  the  aurface  of  a  flat  sheet  of  paper  the  true  shape  of 
a  solid  object,  and  various  niethoda  have  been  devised  to  over- 
come this  difficult  J. 

A  perspecUve  drawing  (Fij;.  81)  rejireseiits  tlie  object  as  seen 
from  one  point  of  view,  and  the  result  ix  a  picture  suoh  as 


'A  perapoetlvo  drawing 


might  be  obtained  by  photography.     As  a  inorlnng  drawing,  the 
object  of  which  is  to  furnish  the  workman  with  all  details  of   ;. 
construction,  such  a  view  is  unsatisfactory. 

An  iMnnetric  drawing  (Fij;.  82),  which  attempts  to  conibiiie 
pictorial  effect  with  correct  pi-oportion,  is  possibly  better  than  a 
perspective  sketch,  but  it  is  also  of  limited  application. 

The  only  really  satisfactory  method  is  to  make,  from  sevOTuA 
different  points  o/  view,  geparate  drawings  whict  reptftaeiA  ^ilha 


BO        A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

details  of  the  object  in  accurate  proportion.  Tliie  last  method 
is  known  aa  orthographic  prajMUon.  Tliree  riewH  &re  generally 
repi'esented ;  that  view  which  Bhowa  the  appearance  as  seeo 
directly  from  above  is  called 
a  idan ;  those  which  repre- 
sent views  from  positions  on 
a  level  with  the  object  are 
called  slevatloiu ;  and  those 
which  show  internal  details, 
obtained  by  supposing  the 
object  cut  through  in  various 
directions  by  planes,  are  called 


In  orthographic  projection, 

be  views  are  supposed  to  be 

projected"  from  the  object, 

on  to  planes  called  co-ordinate 

planet.   Thus,  in  Fig.  83,  which 

of  these  planes  and  a  solid  object, 

i.F.  is  a  hoTlxontol  plane.    Suppose 

> 


is  a  pictorial  (isouictiic)  viev 

F.v.p.  is  a  vertical  jOxat,  and 

straight     lines     drawn 

(projected)    from    each 

angle  of  the  object  and 

at   right   angles   to  the 

two  planes.     The  figure 

a'b'ef  is  the  projection 

onr.v.p.    It  is  called  the     „ 

elevation,  and   abed   is      •■ 

the    projection    on    the 

H.p.  ;     it    is    the    plan,     n 

The     two     projections 

represent    what    would 

be  seen  by  any  observer 

looking    at    the    object 

from  the  front  and  fixini 

alwve  respectively.     The  intersection  of  these  two  reference 

planes  is  called  the  groimd  line,  and  is  usually   lettered  ^.- 

Siniilaply,  an  elevation  of  the  object  may  be  pi-ojected  upon 

a  third  plane,  s.v.p. 

It  follows  that  while,  with  the  object  in  any  given  position, 
oniy  one  plan  can  be  drawn,  any  number  of  elevations  may  be 


d:: 


SOME  SIMPLE  SOLIDS  61 

obtained ;  the  only  stipuktion  is  that  the  vertical  plane  of 
projection  shall  be  at  right  angles  to  the  direction  of  the  view. 

The  three  planea  with  their  projectiona  are  represented  on 
one  surface  by  supposing  the  vertical  planes  to  be  revolved 
back  on  their  base  lines  as  hinges,  until  they  ate  in  the  same 
plane  as  the  h.p.  The  part  below  xy  then  represents  tlie  h.p., 
and  the  part  above  xg  the  v.p.  A  comparison  of  Fig.  83  and 
Fig.  84  will  show  how  this  takes  place.  The  dotted  lines  drawn 
from  one  projection  to  another  are  always  perpendicular  to  xt/ 
and  are  called  projectors.  A  uniform  syatem  of  lettering  is 
always  adopted  in  solid  geometry,  and  a  careful  attention  to 
the  lettering  will  aid  in  the  solution  of  the  questions.  '!%«  . 
capital  letter  (A)  indicates  the  point  (or  corner)  ot  an  object  in 
space,  the  aame  letter  in  italics  with  a  da^h  {a')  is  used  for  the 
elevation  of  the  point,  and  the  aanie  letter  without  the  dash 
(a)  for  its  plan.  Additional  elevations  of  the  point  may  be 
indicated  with  the  same  letter  with  a  numeral  (a^). 

Some  Simple  Solids.— The  study  of  solid  geometry  ia  best 
commenced  by  projecting  aonie  of  the  simpler  geometrical  aolids 
such  as  the  cube,  priam,  pyramid,  cone,  cylinder,  etc.  After  this 
it  will  be  necessary  to  conatder  the  projection  of  straight  lines 


Pyramid        Cylinder 


in  different  positions  ;  and  then  inclined  and  ol)lique  planes — 
that  is,  planes  inclined  to  the  rectangular  planes — must  be 
considered. 

A  cube  ia  a  Bolid  figure  bounded  by  six  square  faces  (Fig.  85). 

A  ijtlBm  (Fig.  66)  is  a  soJid  figure  whose  two  ends  aj:e  qI  ^^« 


52 


A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


same  shape  and  size  and  lie  in  parallel  planes.  An  imaginary 
straight  line  joining  the  centres  of  the  ends  is  called  the  aarU. 

A  pyramid  (Fig.  87)  is  bounded  by  a  base  and  a  number  of 
triangular  faces  meeting  at  a  point  called  the  a'pex. 

Both  the  prism  and  the  pyramid  are  named  according  to  the 
shape  of  the  base  ;  they  may  be  either  triangular^  square^  rect- 
angulaVy  or  'polygonal.  A  right  prism  or  pyramid  is  one  that  has 
the  base  at  right  angles  to  the  axis.  If  the  base  is  not  at  right 
angles  to  the  axis  the  prism  or  pyramid  is  said  to  be  ohliqiie. 

A  cylinder  (Fig.  88)  is  a  prism  which  has  a  circular  base. 

A  cone  (Fig.  89)  is  a  pyramid  with  a  circular  base.  A  conical 
surface  may  be  supposed  to  be  developed  by  revolving  a  right 
angled  triangle  around  one  of  the  sides  containing  the  right 


Cone 

Fig.  89. 


Sphere 

Fig.  90. 


Tetrahedron     Octahedron 


Fig.  91. 


Fio.  92. 


angle.  Any  straight  line  joining  the  apex  to  any  point  on  the 
circumference  of  the  base  is  called  a  generator  of  the  cone. 

A  sphere  (Fig.  90)  is  generated  by  a  semi-circle  revolving 
upon  its  diameter.  Every  part  of  the  surface  is  equidistant 
from  the  centre. 

A  tetrahedron  (Fig.  91)  is  a  solid  having  four  equal  faces  all 
of  which  are  equilateral  triangles.  It  is  a  particular  kind  of 
triangular  pyramid. 

An  octadedron  is  a  solid  having  eight  equal  faces  all  equi- 
lateral triangles  (Fig.  92). 

When  working  the  following  examples  it  is  very  advisable  to 
be  provided  with  the  necessary  geometrical  solids,  and  also  a 
piece  of  stiff  paper  or  cardboard,  with  the  xy  line  drawn  across 
the  middle  of  it.  By  folding  this  paper  along  xy  a  model  of 
the  co-ordinate  planes  is  obtained,  and  the  student  can  with  the 


PROJECTION  OF  SOLIDS. 


53 


aid  of  this  and  the  solids  get  a  clear  conception  of  the  pro- 
jections required.  Much  depends  upon  the  position  in  which 
the  solid  is  to  be  drawn  ;  perhaps  the  plan  will  have  to  be 
drawn  first,  though  sometimes  the  plan  can  only  be  obtained 
after  the  elevation  has  been  drawn  ;  while  it  frequently  happens 
that  neither  the  plan  nor  the  elevation  can  be  drawn  at  once  in 
the  required  position.  In  this  case,  supplementary  drawings 
must  be  made  first,  and  from  these  the  necessary  projections 
are  obtained.  In  the  projection  of  lines,  a  pencil  or  a  straight 
piece  of  wire  can  be  used  advantageously  ;  while  for  inclined 
and  oblique  planes  the  set  square,  or  a  triangular  piece  of  card- 
board, is  useful  for  purposes  of  illustration. 

Example  1. — To  draiv  the  plan  and  elevation  of  a  cube  when 
one  face  U  in  the  H.P.  and  a  second  face  inclined  to  the  V.P, 
at  30".     Draw  a  new  elevation  of  the  cube  mi  any  new  xy. 

Fig.  93  shows  the  plan  and  elevation  required.     It  will  be 
seen  that  the  plan  is  a 
square,      and      as      all  3<       b      (J        C 

the  vertical  faces  of  the 
solid  are  inclined  to  the 
vertical  plane,  it  is  first 
necessary  to  draw  the 
plan,  and  then  project 
the  elevation  from  it. 
The  projected  must 
always  be  at  right  angles 
to  ocy.  For  the  second 
elevation,  let  afxf  be 
the  ground  line.  Pro- 
ject from  the  plan  (at 
right  angles  to  j/y')  and 
measure  the  height  of  a^,  6^,  c^,  d'^^  equal  to  the  height  of 
a',  6',  c',  d\  respectively. 

Example  2. — To  draw  the  plan  and  elevation  of  a  square-based 
pyramid^  when  the  base  lies  in  the  H.P.  aiid  one  edge  of  the  base  is 
inclined  to  tJie  V.P.  at  45°.  Draw  a  new  elevation  on  any  vertical 
plane  not  parallel  to  either  a  diagonal  or  a  side  of  the  base. 

Fig.  94  shows  the  required  projections.  In  this  example  it  is 
first  necessai'y  to  draw  the  plan,  and  from  it  to  draw  projectors 
which  give  the  poaition  of  the  elevation.    Tlie  iiev^  e\vi\^\AQVi\& 


Pio.  93. 


84        A  MANUAL  OP  CARPENTRY  ANU  JOINERY. 

obtained  by  first  drawing  s!^  and  then  projecting  from  the 
points  ia  plan  at  right  angles  to  ^y,  marking  the  height  of  the 
n  the  Bi'»c  alevatioo. 


Fig.  95  shows  the 
completed     projec- 


Pia.  M.  Flo.  06. 

ExAHPLE  2.— To  draw  the  plan  and  elevation  of  a  right 
octagonal  pi/ramid,  when  the  axit  it  horizontal,  the  bate  in  the 
V.P.  and  oiie  edge  of  the  bate  vertical. 

In  this  example  it  will  be  necessary  to  draw  the  elevation 
,;  .  before     the     plan. 

X.,A 

•^V  ExAMrLB  4.— Til 

draw  the  plan  and 

w,-  elevation  of  a  right 

pentagonal     prttm, 

■when  the  long  edge* 

/Tt,    are  piiruUel  to  the 

V.l'.,  inclined  to  the 

'^-^    /  ff.P.  at  35°,  aiid  one 

'  edge  of  the  base   i< 

horiiontal. 

pomible   to    obtaia 


PROJECTION  OF  SOLIDS  AS 

the  required  projections  without  first  drawing  an  auxiliary  view. 
Fig.  96  shows  the  projectiona  of  the  prism  in  an  upright  position, 
and  with  the  base  in  the  horizontal  plane.  A  new  x'^  is  then 
drawn  at  an  angle  of  35°  to  the  elevation  of  one  rectangular  face ; 
the  projectors  di'awn  at  right  angles  to  3iy'  will  then  contain  the 
angular  points  of  a  second  plan  which,  with  the  elevation 
already  drawn,  will  give  the  projections  required.  These  points, 
a}>,e„  etc.,  lie  on  the  projectoii<  at  distances  from  3!y'  e(|ual  to 
the  distances  from  xy  of  the  corresponding  points  in  the  plan 
dbc,  etc.  Join  these  points  and  complete  the  required  plan  in 
the  manner  shown  in  the  figure. 

Example  b.—Tv  drain  the  projections  of  a  rigM  h^tagonal 
pyramid   wken  (1)  one 
triangular  face  lies  in  the  ~ 

JI.P.,  (2)  one  triangidar 
face  it  vertical  and  per- 
pendicular to  tite  V.P, 

This  example  also 
involvea  the  use  of 
additional  ground  lines, 
as  the  required  pro- 
jections cannot  be 
drawn  direct  from  the 
data  given  (Fig.  97). 
Fii-st  draw  the  plan 
and  elevation  of  the 
pyramid  when  the  base 
lies  in  the  h.p.,  and  one 
triangular  face  is  at 
right    anglt 


i  the 


projectiona  of  that 
triangular  face  which 
is  at  right  angles  to 
the  vertical  plane. 
Draw  a  second  ground 
line  j-y  through  a'o'. 
IJraw  projectors  from 
the  elevation  at  right 
angles  to  ^>/, 


previous  example,  thus  obtaiuiiig  thi 


tj>.cfilfi,f,fip^    Tlvia 


56 


A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


plan  and  the  elevation  are  the  projections  of  the  pyramid  when 
one  triangular  face  (OAB)  lies  in  the  h.p.  To  obtain  the  pro- 
jections of  the  figure  when  one  triangular  face  is  vertical,  draw 
another  ground  line  xh/^  at  right  angles  to  a'o\  "By  projecting 
from  the  elevation,  another  plan  o^^^A^^f^S^^  ^^  obtained 
which  gives,  with  the  elevation,  the  projections  of  the  pyramid 
with  one  triangular  face  {OAB)  vertical. 

Example  6. —  To  draw  the  projections  of  a  cylinder  when  (1)  the 
axis  is  vertical^  (2)   the  axis  is  horizontal  and  parallel  to   the 
V.P.J  (3)  the  axis  is  honzo7ital,  aiid  inclined  to  the  V.P.  at  45**. 

Fig.  98  shows  the  projections  of  this  solid  when  the  axis  is 
vertical ;  either  the  plan  or  the  elevation  may  be  drawn  first. 


FiQ.  98. 


Fia.  99. 


Fig.  99  gives  the  projections  when  the  axis  is  horizontal  and 
parallel  to  the  vertical  plane.  It  will  be  seen  that  in  this  case 
the  plan  and  the  elevation  are  of  the  same  size  and  shape.  In 
the  third  case  (Fig.  100),  as  the  axis  is  horizontal,  the  plan — which 
is  a  rectangle — is  drawn  first.  As  the  ends  of  the  cylinder  are 
neither  parallel  nor  perpendicular  to  the  vertical  plane,  the  shape 
of  their  elevation  will  be  a  curved  line.  This  particular  kind  of 
curved  line  (the  appearance  of  a  circle  seen  obliquely)  is  named* 
an  ellipse.  After  drawing  the  plan,  project  from  it  an  elevation 
on  a  vertical  plane  parallel  to  the  ends  of  the  cylinder.  This 
elevation  is  a  circle.  Through  the  centre  of  this  circle  draw  the 
line  a'b'  parallel  to  a'?/',  and  the  perpendicular  lines  c'c\  d'd\  etc. 
Project  the  plans  of  these  lines  on  to  the  plan  of  the  cylinder. 
The  required  elevation  can  now  be  drawn  by  projecting  from 


PEOJECTION  OF  SOLIDS. 


67 


the  points  aa,  hb,  fc,  dd,  etc.,  utid  measuring  the  heights  above 
.ay  equal  to  the  heights  of  the  sanie  pointa  above ^y  as  shown. 
Even  carves  drawn  thi'ougli  the  points  give  the  two  ellipses 
required.  To  undei-stand  these  enaniples  clearly,  the  method 
of  lettering  must  be  carefully  followed  and  adopted. 


Example  T.^To  draw  the  plan  and  devalion  of  a  right  cone 
vihen  (1)  the  base  is  in  the  horizontal  plane,  (2)  a  gen^ator  (a 
straight  line  draiim  from  the  apex  to  a  point  in  the  circumference 
of  the  base)  lies  in  the  H.P.,  and  the  aans  it  parallel  to  the  V.P. 

Fig.  101  shows  the  projeetionn  of  the  cone  when  the  base  is  in 
the  n.p.  The  second  position — using  the  elevation  already 
diawn— can  be  obtained  by  drawing  a  new  x'y'  through  one  of 
the  sides  o'T  of  the  elevation  and  projecting  from  it  a  new  plan, 
the  distances  of  the  points  in  it  from  a^y'  being  equal  to  the 
distances  fioiii  the  same  points  on  the  fii'st  plan  drawn.  In 
order  to  get  the  ellipse  which  is  now  the  plan  of  theJmse,  points 
1,  2,  3,  4,  5,  6,  7.  are  fixed  in  the  first  plan,  projected  to  the 
elevation,  and  then  to  the  required  second  plan  as  shown  in  the 
agupe. 


68        A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


PROJECTION  OF  LINES. 

Lines. — When  a  line  is  parallel  to  both  planes  of  projection, 
its  true  length  is  shown  in  both  plan  and  elevation  (Fig.  102). 
When  a  line  is  piit-allel  to  one  plane  of  projection  only,  its  pro- 
jection upon  that  plane  shows  its  true  length.  Figs.  103  and  104 
show  two  examples  of  a  line  inclined  to  the  n.p.  and  parallel  to 
the  v.p.     The  length  of  the  plan  of  this  line  depends  upon  its 


a  b   a 

Fid.  102.  Fio.  103. 


inclination  to  the  n.p.  If  the  line  is  vertical  then  its  plan  is 
a  point.  Fig.  105  shows  a  line  which  is  parallel  to  the  h.p.  and 
is  inclined  to  the  v.p.  The  length  of  the  plan  of  a  horizontal 
line  is  always  equal  to  the  length  of  the  line,  while  the  length 
of  the  elevation  varies  according  to  the  inclination  of  the  line 
to  the  v.p.  (Figs.  105  and  106). 

More  difficulty  is  found  in  determining  the  projections  of 
lines  which  are  parallel  to  neither  plane  of  projection.  Neither 
the  plan  nor  the  elevation  gives  the  true  length  of  the  line.  As 
already  explained  in  the  case  of  solids,  auxiliary  construction  is 
necessary  in  such  circumstances.  It  is  heie  impossible  to  con- 
sider more  than  a  few  of  the  various  ways  in  which  lines  may 
be  placed.  It  is,  however,  necessary  to  know  that  the  sum  of 
the  inclinations  of  a  line  to  the  two  planes  cannot  be  together 
greater  than  90**.  The  ti*aces  of  a  line  are  the  points  where 
the  line  intersects  the  co-ordinate  planes,  the  horizontal  trace 
(ii.T.)  being  the  point  where  the  line  meets  the  n.p.,  and  the 
vertical  trace  (v.t.)  where  it  meets  the  v.r. 


PROJECTION  OF  LINES. 


59 


\ 


Pio.  lor. 


Example  1. — To  draw  the  projections  of  a  straight  line  oj  given 

length  which  is  inclined  to  the  H.P.  at  45"  and  to  the  V.P.  at  20°. 
From  a  point  0  in  xi/  (Fig.  107),  draw  OA  (above  xt/)  of  the 

required  length  and  inclined  to  xi/  at  45°.     From  -4,  draw  the 

projector  Aa.    Then  Oa  is  the 

length  of  the  plan  of  any  line 

of  this  length  and  inclination. 

From  0  draw  OB  (below  xi/) 

also  the  real  length  of  the  line 

and  inclined  at  20°  to  an/,    A 

projector  from  B  Ui  xy  gives 

Oh    as    the    length    of    the    y 

elevation  of  this  line.     If  the 

two    extremities    of    the  line 

are  in  the   coordinate  planes 

then  one  end  is  at  the  height 

A  in  the  v.  p.  and  the  other  end 

is  in  a  horizontal  line  on  h.p., 

which  is  at  a  distance  from 

xjf  equal  to  the  distance  Bh.    What  is  now  required  is  to  arrange 

these  lines  in  the  same  projectors  and  in  their  proper  position. 

Taking  the  length  of  the  plan  Oa  as  radius,  and  with  a  as  centre, 

draw  the  semicircle.     The  plan  of  the  required  line  will  be  a 

radius  of  this  semicircle.     Now  take  the  length  of  the  elevation 

Oh  as  radius,  and  with  A 
as  centre  draw  the  arc 
intersecting  xy  at  c\  Join 
Ac'  and  draw  a  projector 
from  c'  to  intersect  the 
semicircle  in  c.  Re-letter 
the  point  A  as  a',  then  a'c' 
is  the  elevation  and  ac  the 
plan  of  the  given  line. 

Example  2.—  To  draw 
the  projections  of  a  straight 
line  of  given  length  which 
is  inclined  to  the  H.P.  at 
30°  and  to  the  V.P.  at  60°. 
From    a  point  0  in  .rj/ 

(Fig.  108),  draw  OA  inclined  at  30°,  and  OB  at  60°  to  xij^  both 

being  of  length  equal  to  the  length  of  the  line.     Pro\fec\.OT^ 


60 


A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


drawn  from  A  and  B  to  xy  give  the  lengths  of  the  plan  and  the 
elevation  i-espectively.  With  a  as  centre  and  radius  aO  draw 
the  semicircle,  a  radius  of  which  is  the  required  plan.  With  A 
as  centre  and  the  length  of  the  elevation  {Oh)  as  radius,  draw 
the  arc  which  just  reaches  to  yx  at*  a.  Had  the  sum  of  the 
inclinations  been  less  than  90**,  this  length  of  elevation 
would  have  intersected  xy  somewhere  between  0  and  a  as 
it  did  in  the  previous  example.  As  the  elevation  is  per- 
pendicular to  xyy  the  plan  will  also  be  perpendicular  to  xy ; 
that  is,  will  be  a  continuation  of  the  same  line  as  shown  in 
the  figure ;  ah'  is  the  elevation  and  ah  the  plan  of  the  given 
line. 

Example  3. — Oiven  the  plan  and  elevation  of  a  straight  line,  to 
dete^'mine  its  length  and  inclination  to  hoth  planes  of  projection. 

Let  a'h'  and  ah  be  the  given  projections  (Fig.  109).     Witb  h  as 
centre  and  ha  as  radius  turn  the  length  of  plan  into  xy  bs  2A,  A. 

Join  Ah',  Then  Ah'  is 
the  true  length  of  the 
line,  and  the  angle  h'Ah 
(usually  marked  0)  gives 
the  inclination  to  the  h.p. 
With  a'  as  centre  and 
a'h'  as  radius,  turn  the 
*^  elevation  into  xy  as  at 
B.  Join  aB^  then  aB  is 
also  the  true  length  of  the 
line,  and  the  angle  aBa' 
(usually  marked  </>)  is  the 
inclination  to  the  v.p. 

Another  method  of 
working  this  example  is 
shown  in  Fig.  110.  Let  ah'  and  ah  be  tlie  given  projections.  At 
the  end.s  a  and  h  of  the  line  draw  perpendicular  lines  as  shown. 
On  the  perpendicular  from  a  mejisure  a  length  aA  equal  to  the 
height  of  a'  above  xyy  and  on  the  line  from  h  measure  a  length  hB 
equal  to  the  height  of  h'  above  xy.  Join  AB  and  produce  it 
until  it  meets  ah  produced  at  //.  Then  AB  is.  the  true  length  of 
the  line,  and  the  angle  Bllh  (6)  gives  the  inclination  to  the 
horizontal  plane.  To  obtain  the  inclination  to  the  vertical  plane, 
draw  perpendicular  lines  from  a'  and  6',  and  measure  on  each  of 


Fig.  109. 


PROJECTION  OF  LINES. 


61 


these  the  distance  that  the  corresponding  point  is  in  front  of 
the  vertical  plane  (its  distance  below  xy\  Join  ^'JS'aud  pro- 
duce it  until  it  meets  'a!h' 
in  V.  The  line  A'E  is  the 
real  length  of  the  line,  and 
the  angle  A!Va!(i\i)  is  the 
inclination  to  the  vertical 
plane.  The  points  V  and 
H  are  the  vertical  and 
horizontal  traces  of  the 
line.  If  this  example  (Fig. 
110)  is  drawn,  and  then  the 
triangle  a'A'  V  is  cut  to  fold 
upon  a'  r,  and  the  triangle 
bBH  is  cut  to  fold  upon  Jib, 
by  turning  these  triangles 
at  right  angles  to  the  planes 
and  folding  the  co-ordinate 
planes  at  right  angles  to 
each   other   upon  jKy,    the  '°' 

lines  AB  and  A'B'  come  together  as  illustrated  in  Fig.  111. 


Fio.  111. 


62        A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

INCLINED  AND  OBUQUE  PLANES. 

In  addition  to  the  co-ordinate  planea,  lucliuftd  and  obUqne 

planes  are  to  be  considered.  Iq  orthographic  projection  these 
can  only  be  shown  by  their  Unes  of  intersection  with  the 
rectangular  co-oidinate  planes.  The  intersecting  lines  are  calleil 
traces  ;  that  which  intersects  the  vertical  plane  is  called  the 
vertical  trace  (v.T.),  and  the  one  which  intei-secta  the  horizontal 
pUne  is  the  horizontal  trace  (h,t,).  Two  planes  always  intersect 
in  a  straight  line,  and  three  planes  may  intersect  in  a  straight 
line  or  in  a  point.  If  the  plane  ia  perpendicular  to  one  plane  ot 
projection,  and  inclined  to  the  other,  it  is  usually  nasied  an 
Inclined  plane.  If  it  niake.'t  an  acute  angle  with  both  planes  of 
projection  it  is  termed  an  oi>llqne  plane. 

The  method  of  determining  the  inclination  of  these  planes  to 
the  planes  of  projection  is  to  suppose  them  cut  through  at  right 
angle-i  to  their  line  of  intersection. 

Tlie  cone  is  used  extensively  in  solvrng  questions  on  oblique 
planes.     By  drawing  the  pi-ojections  of  a  cone  having  its  base 


on  the  ii.p.  and  a  generator  (p.  52)  in  the  oblique  plane  (Fig. 
112),  the  base  angle  of  the  cone  gives  the  angle  between  the 


INCLINED  AND  OBLIQUE  PLANES. 


and  a  generator  in 
equal    to    the    in- 
clination    of     the 
plaae  to  the  v.p. 
Oblique  pli 
be      easily      con 
vertfid  into  aimpli 
inclined        ph 
by    altei-ation     of 
pround     line,    i.e. 
by   placing  xj/   at 
right     angles     to 
the  n,T.    The 
of  the  incli 
cannot  he  greater 
than  18U°  nor  less 
than  90°. 
Figs.    114    and 


placed  with  ila  base  in  the  vertical  plar 
1  oblique  plane  (Kig.  113),  hrw.  a  base  a 


64        A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

116  show  some  of  the  different  poBitionB  in  which  inclined 
and  oblique  planes  can  be  placed  Figs.  115  and  117  show 
the  f^onietrical   projections  of  the  same.     Fig.  115  (1)   is  an 


•^ 

•si 

VT. 

1 

\z 

,3 

a£ 

'\ 

HT. 

4 

inclined  plane  wliidi  is  pcipendiculai'  to  the  vertical  plaoe. 
Fig.  115  (2)  is  a,  vertical  plane  which  is  inclined  to  the  vertical 
plane.    Fig.  115  (3)  is  a  horizontal  plane,  and  baa  therefore  only 


one — a  vertical — trace;  while  in  Fig.  115  (4)  a  vertical  plane 
which  ia  parallel  to  the  v.r.  is  shown  ;  aa  will  l)e  seen,  it  has 
only  one— a  horizontal— trace.     Figa.  116  and  117  ahow  oblique  • 
planes,  and  it  is  these  which  usually  present  the  most  difficulty 
to  the  student  of  geometry.     Fig,   117   (2)   shows   an   oblique 


INCLINED  AND  OBLIQUE  PLANES. 


65 


plane,  the  traces  of  which  are  parallel  to  xy.  It  should  be 
noticed  that  when  the  traces  of  a  plane  intersect,  they  always 
do  so  in  the  ground  line. 


Fio.  117. 


Example  1. — To  determine  the  traces  of  a  plane  which  is  inclined 
to  the  H.P.  at  40°,  and  is  perpenidicular  to  the  Y.P. 

The  solution  of  this  example  is  very  simple,  as  it  only 
consists  of  two  straight  lines  in  addition  to  ocy.     One  is  drawn 


-y 


Pig.  118. 


above  ocy  at  an  angle  of  40"  to  it,  and  the  other  one  is  drawn 
perpendicular  to  ^  so  that  the  two  intersect  on  xy  as  shown  in 
Fig.  118. 

Example  2. — A  rectangular  chimney  shaft  penetrates  a  sloping 
roof  the  inclination  of  which  is  60°.  Determine  the  tnie  shape  of 
the  hole  in  the  roof. 

The  roof  surface  can  be  considered  as  a  plane  to  be  shown  by 
its  traces.    In  Fig.  119  let  v.t.  and  h.t.  be  tbe  traces  oi  \)^e 


JSm€^»tfm 


E 


66 


A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


plane,  and  abed  the  plan  of  the  chimney  shaft.  Draw  the 
elevation  of  the  shaft,  showing  it  cut  by  the  plane.  Suppose  the 
plane  of  the  roof,  with  the  section  of  the  shaft,  to  be  revolved 


Pio.  119. 


upon  the  h.t.  into  the  h.p.  ;  ABCD  gives  the  shape  of  the  hole. 
It  will  be  seen  that  the  greater  the  inclination,  the  longer 
will  be  the  rectangular  hole  in  the  roof. 

Example  3. — Given  the  traces  of  an  oblique  plane,  to  determine 
the  inclination  of  the  plane  to  both  the  H.P.  and  the  V.P, 

Let  v.T.  and  h.t.  (Fig.  120)  be  the  traces  of  the  given  plane. 
Draw  the  projections  of  a  semi-cone  having  its  axis  a'b'  in  the 
vertical  plane,  the  apex  a'  in  the  given  v.t.  and  its  base 
(a  semi-circle)  ced  in  the  h.p.  and  lying  tangentially  to  the 
given  H.T.  Then  the  base  angle  (6)  of  the  cone  gives  the 
inclination  of  the  plane  to  the  h.p.  To  determine  the  inclina- 
tion of  the  plane  to  the  v.p.,  draw  the  projections  of  a  second 


INCLINED  AND  OBLIQUE  PLANES. 


67 


semi-cone,  having  the  axis  mn  in  the  h.p.,  and  the  apex  m  in 

the  given  h.t.,  while  the  base  is  in  the  v.p.  and  tangential  to  the 

v.T.      The  base  angle 

(</>)  of  this  cone  gives 

the  inclination  to  the 

v.p. 

Example  4. — Given 
the  traces  of  an  oblique 
plane^  to  convert  it  into 
a  simple  inclined  plane, 
and  determine  its  in- 
clination to  the  H.P, 

Let  v.T.  and  h.t. 
(Fig.  121)  be  the  given 
traces.  Draw  any  new 
ground  line  {x'y')  at 
right    angles    to    the  ^^^^^20. 

H.T.    Draw  the  plan  of 

a  horizontal  line  at  any  height  (say  1")  on  this  plane.    The  plan 
of  a  horizontal  line  lying  on  a  plane  is  always  parallel  to  the 


H.T.  of  the  plane  containing  it.  To  draw  this  line,  first  draw  a 
line  a'h'  parallel  to  xy  at  a  height  of  V  above  it.  Where  this 
line  cuts  the  v.T.,  as  at  a',  drop  a  projector  to  an/.    I>T«t>N  ob 


«S        A  MANUAL  OF  OARPENTBY  AND  JOINERY. 

parallel  to  h.t.  This  is  the  plao  of  the  line.  Produce  ah 
beyond  j^y  and  make  a'  equal  id  height  to  a'  (l").  This  gives  a 
point  in  the  new  vertical  trace.  As  the  traces  of  a  plane  alwajs 
meet  in  the  ground  line,  the  v.t.  is  drawn  through  the  points 
a*  and  the  intersection  of  h.t.  hs  shown.  The  angle  (0)  which 
this  line  makee  with  yy  givea  the  inclination  of  the  plane  to 
the  H.p. 

ExAUPLB  6. — Determine  the  traeee  of  a  plane  whuA  w  indinei 
to  the  H.P.  at  45°  amd  to  the  V.P.  at  65°. 

To  solve  this  example  it  is  necessary  to  suppose  two  cones,  one 
with  a  base  angle  equal  to  the  inclination  to  the  H.P.,  and  the 


other  with  a  base  angle  equal  to  the  inclinatiou  to  the  v.p.,  each 
cone  to  envelop  one — the  same— sphere  (Fig.  122).  On  any  point 
0  in  ^  (Fig.  123)  draw  a  circle  (any  radius)  as  shown.  This 
circle  is  the  plan  and  elevation  of  a  quarter  of  a  sphere  having 
its  centre  in  the  ground  line.  Draw  the  plan  and  elevation  of 
a  semi-cone  having  a  base  angle  of  45°,  its  base  being  on  the 
u.p.,  its  axis  in  the  v.p.,  and  of  such  size  that  it  just  enveleps 
tie  ,quart«r-8phere.  Draw  a  second  semi-cone  with  the  baee 
in  the  v.p.,  the  axis  on  e-p.,  with  a  base  angle  of  65°,  and  also 


INCLINED  AND  OBLIQUE  PLANES. 


09 


enveloping  the  quarter- sphere;  The  required  traces  are  then 
drawn — one  through  the  apex  of  the  first  cone  and  tangential 
to  the  base  of  the 
second ;  the  other 
through  the  apex  of 
the  second  and  tan- 
gential to  the  base  of 
the  first,  as  shown  in 
Fig.  123,  which  is  the 
geometrical  solution  of 
the  example. 

SECTIONS. 

The  section  of  a  draw- 
ing is  the  representation 
of  a  cut  part. ;  Many  of 
the  details  of  construc- 
tion can  only  be  shown 
by  means  of  a  section. 
As  an  illustration  of 
this,  Fig.  124  is  the  plan  Fia.  123. 

of  a  simple  carpenters' 

joint.     From  tbis  plan  alone  it  is  not  possible  to  determine  the 
exact  kind  of  joint.     Figs.  125  to  128  show  sections,  in  the 


1 

1 

1 

J 

1 

1 
1 

1 

1 

\ 

1 
1 

$ 

m 

1 

1 

1 

1 

.... 

7^ 

.~J 


— .b2 


Fio.  125.      Fio.  126.     Pia.  127.     Fro.  128. 


Fio.  124. 


plane  AB^  of  four  different  kinds  of  joint,  of  each  of  which 
Fig.  134  may  be  the  plan. 


TO        A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

Example  l.~Fig.  129  thoicta  leetum  of  a  piece  ofmtxddmg. 
To  determine  tie  section  made  taken  Ike  TTundding  tt  cut  at  an  tm^ 
of  45°  with  the  long  edges. 

Draw  xi/  and  aleo  the  plan  of  a  short  length  of  the  uiould- 
ing.      Show    bj    iU    trace    the    vertical    plane    cutting   tbe 


moulding  at  an  angle  of  45°  with  the  long  edges.  By 
assuming  this  H.T.  to  be  a  new  ground  line  (n^H^),  projoctoi'B 
drawn  through  the  plans  of  the  edges  of  the  moulding  at 
right  angles  to  the  b.p.  give  the  increased  width  required.  As 
the  cutting  plane  is  vertical,  the  heights  of  the  points  above 
xy  are  transferred  to  these  projectors,  and  the  section  is 
completed  as  shown. 

ExAUPi.li  2. — To  determine  the  section  made  by  a  korizontal 
fJane  cutting  throvgk  a  given  triangtdar-based  pyramid. 

Let  a'b'ifo'  and  abco  (Fig.  130)  lie  the  pivjectiona  of  the  given 
pyramid.  Draw  y.T.  the  vertical  trace  of  the  cutting  plane. 
J>raw  projectors  from  <l^f,  the  points  where  the  cutting  plane 


paeaes  through  the  elevation  of  the  inclined  edges  of  the  solid, 
to  meet  the  plans  of  the  same  lines,  aa  a,td,e,f.  By  joining  def 
the  required  section  is  obtained. 


Example  3. — Oiven  a  hexagonal  pyramid,  to  draw  the  lection 
made  by  a  plane  inclined  at  45°  cutting  through  it. 

Let  Fig.  131  be  the  projections  of  the  pyramid.  Draw  the 
traces  v.t.  and  h,t.  of  the  cutting  plane  as  shown.  Letter  the 
figure  as  indicated.  Draw  projectors  fium  g'h'fl^l'm'  to  the 
plan,  thua  obtaining  gkjilm.  The  requii'ed  section  is  obtained 
by  using  h.t.  as  a  hinge,  and  turning  the  points  g'h'J'i:'l'm'  into 
x^,  and  then  projecting  them  at  right  angles  to  xy  until  they 
meet  lines  drawn  through  the  corresponding  points  in  the  plan 
and  parallel  to  xj/. 

An  alternative  method  of  drawing  this  section  is  shown  in  the 
figure.  Id  this  the  v.t.  is  considered  as  a  new  ground  line,  and 
projectors  are  drawn  from  the  points  where  v.t.  cuts  the  eleva- 
tion, at  right  angles  to  it.  The  distances  of  the  points  below  xy 
are  transferred  to  theee  projectors,  thus  giving  the  true  shape  of 
the  section. 


72 


A  MANUAL  OP  CARPENTRY  AND  JOINERY. 


ExAUPLB  i.^To  determine  the  eection  made  by  a  plane  evlling 
a  a/Under  at  an  angle  of  30'  to  the  axi». 

Let  Fig.  132  be  the  projections  of  the  cylinder,  wLich  is 
horizontal,  and  h,t.  the  horizontal  trace  of  the  vertical  cutting 
plane.      This   section— which    ia  an  ellipaft— ia   obtained  bf 


marking  on  the  surface  of  the  cylinder  a  number  of  horizontal 
linea  as  nearly  equidistant  a»  possible,  and  projecting  these  m 
shown  in  the  hgure. 

Sections  of  the  Cone. — The  consideration  of  the  sections  of 
the  cone  is  of  some  importance.  The  sections  obtained  are 
known  as  conic  sections.  The  shape  of  the  section  depends 
upon  the  way  the  cone  is  cut.  Any  section  of  the  cone  taken 
at  right  angles  to  the  asis  is  a  oirole.  If  the  cuttiog  plane 
passes  through  the  apex  the  shape  of  the  section  is  an  Isosodes 
triui^e.  If  the  cut  is  other  than  at  right  angles  to  the  axis, 
and  passes  through  opposite  generators  of  the  cone,  the  section 
is  an  sUipae  ;  when  the  section  is  obtained  by  a  plane 
parallel  to  a  generator  the  section  is  a  parabola ;  while  the 
section  made  by  a  plane  cutting  the  cone  parallel  to  the  axis  is 
called  a  byperbola. 


tFig.  133  shows  in  plan  the  cireular  sectinti  made  iiy  a  hori- 
nital  cutting  pliuie  at  right  angles  to  the  axis.  The  »ixe  of  the 
section  ia  determined  by  the  size  of  the  cone,  the  apex  angle, 
and  by  the  distance  that  the  cutting  plane  ia  from  the  apex 
of  the  cone.  In  the  elevation  of  the  same  figure  is  shown  the 
section  of  the  cone  when  cut  by  a  vertiail  plane  JfjV,  which 
paaaes  through  the  axia.  The  shape  of  the  section  is  an  isoscelea 
triangle. 


['  The  outline  of  some  of  these  conic  sections  may  also  be  con- 
ISered  as  having  been  traced,  by  a  point  moving  along  a  curved 
path,  and  having  a  fixed  relatiunship  to  a  given  line,  the  directrix, 
and  a  given  point,  the  fmtts,  or  to  two  given  points,  tlie/oCT. 

Tbe  EUipBe  bas  two  axes  which  bisect  each  other  at  right 
angles :  tlie  major,  or  trauaverBe  axis  which  ia  the  longer  ;  and 
the  minor  or  conjugatB  axis.  Two  points  on  the  major  axia  are 
called  ftici,  and  ;ui  im|nirtaiit  piopclty  of  this  Hf;uie  is  that 
the  Burn  of  any  two  straight  lines  drawn  ttma  the  foci  to  any 

ihe  cnrve  is  equal  to  the  lengtb  of  the  msjor  azia, 
y  (a)  The  alUpee  conBidered  ax  a  conic  section.^  llg,  134  ahows 

e  elliptical  section  nf  the  cone  obtained  by  projection,     v.t. 

dH,v.  are  the  trauM  uf  the  uniting  plane.     The  dutticd  eWv^oib 


74 


A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


shown  in  the  plan  is  the  plan  of  the  section,  and  gives  the 
lengths  of  a  number  of  horizontal  lines  in  the  section,  i.e.  of  the 
lines  of  intersection  of  the  cutting  plane  and  horizontal  sections 
taken  at  different  heights.  To  obtain  the  true  shape  of  the 
section  draw  ajb^  parallel  to  v.t.  and  at  a  distance  from  v.t. 
equal  to  the  distance  of  ah  below  xy.  The  length  of  the  major 
axis  is  determined  by  drawing  projectors  from  1'  and  2'  at  right 
angles  to  v.t.  until  they  meet  a,6,  in  1,2,.  To  obtain  the  length 
of  the  minor  axis,  bisect  1'2'  in  3',  project  from  this  point, 
measure  the  length  of  3  3  in  plan,  and  transfer  to  the  section 
being  drawn  as  at  3,3,.  The  two  axes  are  now  in  position.  Other 
points  through  which  the  curve  is  drawn  are  obtained  by  pro- 
jecting from  4',  5',  6',  7',  then  obtaining  the  length  of  the 
horizontal  line  through  these  points  as  shown  in  the  plan  at 
4  4,  5  5,  6  6,  7  7,  and  transferring  these  lengths  to  the  required 
section  as  indicated  in  the  figure. 

(6)  The  ellipse  curve  considered  as  the  path  of  a  moviiig:  point 

(I.)  Example. — To  construct  the  curve  of  an  ellipse,  the  lengths 

of  the  axes  being  given. 

Let  AB  and  CD  (Fig.  135)  be  the  given  major  and  minor 

axes  respectively.  With 
the  point  of  intersection 
of  the  two  axes  as  centre, 
draw  two  concentric 
circles  having  radii  equal 
to  OA  and  00  respec- 
tively. Draw  equidistant 
diameters  EE,  FF,  GG, 
HE,  as  shown.  Where 
these  lines  meet  the  large 
and  small  circles  draw 
lines  parallel  to  CD  and 
AB  respectively,  until 
they  intersect  as  at  efgh, 

etc.     A  freehand  curve  drawn  evenly  through  the  points  gives 

the  required  curve. 

(II.)  Example. — Given  the  axes  of  an  ellipse,  to  determine  the 
fod  and  draw  the  curve. 

Let  AB  and  CD  (Fig.  13»i)  be  the  given  axes.  Draw  these  so 
that  they  bisect  each  other  at  right  angles  at  0.    With  0  as 


AT     (^ 

c 

1 

1      1^ 

i 

Fio.  13j. 


THE  ELLIPSE. 


75 


Fio.  136. 


centre  and  i40  as  radius,  draw  the  arcs  intersecting  AB  Sit 

F  and  /\.     These  points  are  the  foci  of  the  required  ellipse. 

The    sum     of     any     two 

straight  lines  drawn  from 

the  foci   to   any   point  in 

the  curve  is  equal  to  the 

length  of  the  major  axis. 

Take  any  number,  say  3, 

of  points  between  F  and 

0  (nearest  together  at  ^) 

and  number  them  1,  2,  3. 

With  ^1    as   radius    and 

with  F  and  F^  as  centres 

draw  arcs  on  each  side  of  AB.    With  B\  as  radius  and  J^and 

F-^  as  centres  draw  the  arcs  intersecting  at  a,  a,a^a\  repeat  the 

construction,  having  ^2  and   B2  as   radii   and  F  and  F^  as 

centres ;  and  again  with  AZ  and  J53  as  radii  draw  more  intersect- 
ing arcs.  Through  the 
C  ^^  points  thus  obtained  draw 

the  curve  of  the  ellipse. 

(IIL)  The  workshop 
method  of  applying  this 
construction  is  to  get  a 
length  of  fine  string  and 
fasten  one  end  to  a  pin  at 
F^  twist  it  round  another 
pin  at  E  with  the  inter- 
vening length  stretched  to 
C,  Place  the  pencil  to  move  along  the  string  as  shown  in 
Fig.  137.  The  moving  pencil  point  traces  out  the  elliptical 
curve. 

(IV.)  Example. — To  construct  an  elliptical  curve  hy  means  of 
a  trammel. 

Take  two  laths  of  wood  or  other  material,  having  a  groove 
along  the  middle  of  the  length  of  each,  and  fix  them  so  that 
they  are  at  right  angles  to  each  other,  Obtain  another  lath  of 
wood  having  near  one  end  a  hole  through  which  a  lead  pencil  is 
placed.  Place  two  small  pegs  in  holes  in  this  rod,  such  that  the 
distances  from  the  pencil  to  these  pegs  are  equal  to  the  lengths 
of  half  the  major  and  half  the  minor  axes  i'eiapeet\v^\^.     ^ 


Pio.  137. 


76        A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

moving  this  rod  so  that  the  pegs  slide  in  the  grooves  as  shown 
in  Fig.  138,  the  pencil  traces  out  the  elliptical  curve. 

A  modification  of  the  trammel  method  of  drawing  an  ellipse 
is  to  use  a  strip  of  paper.  Mark,  on  one  edge,  OM  equal  to  the 
length  of  half  the  major  axis,  and  ON  equal  to  half  the  minor 


Pencil 


Fig.  138. 

axis.  Draw  the  axes  of  the  ellipse  at  right  angles  to  each  other. 
On  moving  the  strip  so  that  the  point  M  is  constantly  on  the 
minor  axis  line,  and  N  on  the  major  axis  line,  the  point  0  traces 
the  elliptical  curve. 

The  Parabola. — The  section  obtained  when  the  cone  is  cut  by 
a  plane  parallel  to  a  generator  is  named  a  parabola.  Unlike 
the  circular  or  elliptical  sections  the  curve  of  the  parabola 
is  not  a  closed  curve,  but  extends  indefinitely  unless  terminated 
by  the  base  of  the  cone.  In  Fig.  139  v.t.  and  h.t.  are  the  traces 
of  a  plane  cutting  the  cone  so  that  the  resulting  section  obtained 
by  projection  is  a  parabola.  Draw  af)^  parallel  to  v.t.  and  at  a 
distance  from  it  equal  to  the  distance  of  ah  from  xy.  Circular 
horizontal  sections  are  drawn  in  the  plan,  and  the  lengths  of 
the  horizontal  lines  of  intersection  of  these  planes  with  the 
inclined  cutting  plane  are  obtained  as  shown  at  66,  cc,  etc. 
Projectors  from  a',  h\  c\  etc.,  at  right  angles  to  v.t.  are  drawn,  and 
the  lengths  hh,  cc,  etc.  transferred  to  the  new  projectors  as 
shown  at  b,b^,  c^c^,  etc.  An  evenly  drawn  curve  through  these 
points  gives  a  parabola. 

The  Hyperbola. — Fig.  139  also  shows  the  section  made  by  a 


DEVELOPMENTS  OF  SOLIDS. 


plane  cutting  the  cone  parallel  to  the  axis. 
^exactly  siuiilai'  to  that  desi;ribeJ  for  the  paialiola,  and  will  be 


tamlj  understood  by  reference  to  the  lettering  of  Fig.  139.   It  ia 
knows  ae  the  brperbola. 


DEVELOPMENTS  OF  SOLIDS. 

Thia  ia  a  branch  of  geometry  which  is  apecially  important  to 
the  earpenter  and  joiner.     It  consists  of  unfolding  or  apreiiding- 

mt  auriaces  so  that  the    Q q 

eaet  shape  of  the  cuvev-  ' 

ing     material    may     lie 

Meertained.       Figs.    !40      ;  Ig 

to  142  allow  the  develop-    A 

rnent     of     the     ciibi>,    :i. 

pentagonal  pyramid,  and 

a  cone  respectively.  C 

In  the  cube  six  squares 
are  drawn  to  touch  each 
gthar  as  flhovn,  and  are 


^^ 


78        1  MANUAL  OF  CARPENTRY  AND  JOINERY. 


theu  folded  on  the  lines.  If  such  a  solid  is  made  out  of  stiff 
paper  or  cardboard,  it  is  best  to  leave  narrow  strips  on  some  of 
the  sides,  as  shown  by  the  dotted  lines,  for  gumming  purposes. 


Fia.  141. 


In  the  P3rramid,  the  base,  which  is  a  pentagon,  is  first  drawn, 
and  on  one  side  of  this  is  constructed  an  isosceles  triangle  the 

lengths  of  the  sides  of 
which  are  equal  to  the 
slant  edges  of  the  re- 
quired pyramid.  "With 
0  as  centre,  and  radius 
OA,  draw  the  arc  as 
shown,  and  measure  BG, 
CD,  BE,  and  EA,  each 
equal  to  A  B,  The  pyra- 
mid  can  be  made  by 
folding  the  figure  on  the 
various  lines,  so  that  the 
corresponding  letters 
come  together.  The 
dotted  lines  indicate 
narrow  strips  by  which 
the  pyramid  may  be 
gummed  together. 
The  cone  is  made  out  of  stiff  paper  by  first  drawing  the 
circle  of  diameter  equal  to  the  required  base,  and  then  marking 
out  the  arc  of  another  circle  of  radius  equal  to  the  length  of  a 
generator  of  the  cone,  and  a  length  of  arc  equal  to  the  circum- 
ference of  the  base.  The  teeth-like  projections  around  the 
cii'cle  are  for  gumming  purposes. 


Fio.  142. 


•DEVELOPMENTS  OF  SOLIDS. 


79 


Example  1. — To  draw  the  development  of  a  square  prism  when 
one  end  is  cut  obliquely. 

The  method  of  construction  will  be  clear  from  an  examina- 


FlG.  143. 


tion  of  Fig.  143,  in  which  the  corresponding  points  of  plan, 
elevation,  and  developed  surface  are  similarly  lettered. 


Fig.  144. 


Example  2. —  To  draw  the  development  of  a  cylinder  when  one 
end  is  ciU  off  at  an  oblique  angle  with  the  axis. 
Fig.  144  shows  the  projections   of    the  cylinder,     liv  Okva 


80        A  SfANUAL  OF  CARPENTRY  AND  JOINERY. 

example  the  "atretcb-oiit"  is  equal  to  the  length  of  the 
circumference  of  the  circle,  the  lower  end  is  a  straight  line, 
while  the  upper  end  is  represented  by  a  curved  line,  the 
shape  of  which  is  obtained  by  asguming  a  number  of  vertical 
lines  on  the  surface,  and  determining  the  length  of  each  of 
these  and  transferring  it  to  the  developed  surface  as  shown 
in  the  figure. 

Examples. — To  draw  the  devel(^m,eM  of  a  truneated  hexagonal 
pyramid,  the  top  being  cut  off  at  an  oblique  angle  vnth  ike  axie. 

Let  Fig.  145  be  the  pro- 
jections of  the  pyramid, 
the  part  shown  dotted 
being  supposed  to  be 
removed.  The  base  is  a 
regular  hexagon,  of  size 
given  in  the  plan.  The 
sis  isosceles  triangles 
representing  the  inclined 
faces  are  obtained  as 
shown  in  Fig.  145,  with 
the  exception  that  the 
apex  acgleof  each  ia  cutoff, 
the  exact  length  of  each 
edge  being  obtained  by 
treating  each  edge  as  a 
line,  and  finding  its  true 
length.  The  top  end  is 
obtained  by  finding  the 
true  shape  of  the  sec- 
tion cutting  the  solid,  in  the  manner  indicated. 

Example   4, — To  draw  the  development  of  a  truncated  right 

Let  Fig.  146  be  the  plan  and  elevation  of  the  cone.  The  base, 
which  is  of  course  a  circle,  is  first  drawn.  Develop  the  conical 
surface  as  shown  in  Fig.  146.  On  the  plan  and  elevation, 
draw  a  number  (say  6)  of  equidistant  generators,  determine 
the  length  of  each  of  these  by  turning  it  into,  or  parallel  to, 
the  V.P.,  and  transfer  these  lengths  to  the  developed  surface. 
A  freehand  curve  drawn  through  the  points  will  give  the  upper 
end  of  the  developed  surface.    The  upper  end  of  the  truncated 


DEVELOPMENT  OF  SOLIDS. 


)  be  obtained  as  previously 


cone  JB  of  elliptical  shape,  and  c 
explained  (Fig.  146.) 

The  application  of  this 
work  to  the  determina- 
tion  of  the  covering  of 
peculiarly -shaped  roof 
surfaces  ia  illustrated  in 
the  following  examples, 
which  may  be  taken  as 
typical : 

Fig.  147  showa  a.  roof, 
the  plan,  abed,  of  which 
is  a  square,  and  the  \ 
vertical  sections,  through 
both  AB  and  CD,  are 
aemicirclea.  In  such  a 
roof  the  hips  (p.  216) 
will  be  elliptical  in  out- 
line. The  dhape  of  "  "pj^.j^ 
the  developed  covering 

surface  is  obtained  by  dividing  the  semicircle  (elevation)  into  a 
number  of  equal  parts  aa  shown.     Draw  the  plan  of  each  of  the 


82        A   MANUAL  OF  CARPENTRY  AND  JOINERY. 

horizontal  lines,  of  which  these  points  are  elevations,  and  thus 
obtain  the  lengths  across  the  surface  at  these  places.  Stretch 
out,  OD  one  side  of  the  plan,  a  length  equal  to  the  distance 
along  the  curve  of  the  elevation  from  A  to  4,  and  place 
these  horizontal  Hues  on  this  stretch-out  as  shown,  projectiug 
the  length  from  the  plan.  Draw  a  freehand  curve  through 
the  points  thus  obUined,  Fig.  147  shows  one  quarter  of  the 
roof  surface  developed ;  as  the  plan  is  a  square,  and  the 
sectionR  taken  either  waj  are  the  same  in  this  example, 
the  remaining  three  sides  are  of  exactly  the  same  shape  as 
the  one  shown. 

e 


Fig.  148  shows  a  roof,  the  plan  of  which  is  a  squars,  and  the 
elevation  a  curved  surface  known  as  an  offee.  The  development 
is  obtained  in  exactly  the  same  manner  as  in  the  preceding 
example.  It  is  necessary  to  take  a  number  of  horizontal  lines, 
aa  ahown  in  the  figure  by  their  plans  and  elevations,  and 
then  to  obtain  the  stretch-out  of  the  curved  surface  as  in 
Fig.  147.  Aa  the  drawing  ia  numbered,  an  examination  of  it 
wilJ  make  the  method  clear. 


QUESTIONS  ON  CHAPTER  III.  83 


Questions  on  Chapter  III. 

1.  Draw  the  plan  and  elevation  of  a  square  prism,  of  3  in.  edge, 
and  1*75  in.  high,  when  the  base  is  inclined  at  30°  to  the  H.r.  and 
one  edge  of  the  Imse  is  in  the  H.r.,  and  perpendicular  to  the  v. p. 
Draw  a  second  elevation  upon  a  vertical  plane  which  is  parallel  to 
the  horizontal  edges  of  the  solid. 

2.  Draw  the  plan  and  elevation  of  a  right  pentagonal  pyramid 
(edge  of  base  1'25  in.,  length  of  axis  3  in.)  when  the  base  is  on  the 
H.P.,  and  one  triangular  face  is  perpendicular  to  v.  p.  Draw  a 
second  plan  of  the  solid,  which  will,  with  the  elevation,  be  the 
projections  of  the  solid  when  a  triangular  face  is  on  h.p. 

3.  Draw  the  projections  of  a  cylinder  (base  2*5  in.  diameter,  axis 
1  in.  long)  when  the  axis  is  inclined  to  the  ii.p.  at  45^*  and  is 
parallel  to  the  vertical  plane. 

4.  Draw  the  projections  of  a  straiglit  lino  3  in.  long  in  each  of  the 
following  positions  : 

(a)  inclined  to  the  ji.p.  at  45",  and  parallel  to  the  v. p. : 

(h)  parallel  to  the  ii.p.,  and  inclined  to  the  v. p.  at  30°  : 

(e)  parallel  to  the  ji.p.,  and  inclined  to  the  v. p.  at  60°  : 

{(l)  inclined  to  the  ii.p.  at  30°,  and  inclined  to  the  v. p.  at  45°  : 

(c)  inclined  to  the  h.p.  at  20°,  and  inclined  to  the  v. p.  at  70°. 

5.  The  plan  of  a  line  4  in.  long  is  2 '5  in.  What  is  its  inclination 
to  the  II.  P.  ? 

6.  One  end  of  a  lino  is  3  in.  from  l)oth  planes  of  projecticm,  and 
the  other  end  is  in  xy.  The  length  of  the  line  is  5  in.  Draw  the 
plan  and  elevation,  and  determine  its  inclination  to  the  h.p. 

7.  A  sloping  surface  has  an  inclination  of  45°.  It  is  cut  by  a 
vertical  plane  the  plan  of  which  makes  an  angle  of  45°  with  the 
horizontal  edges  of  the  sloping  surface.  Determine  the  inclination 
of  the  lino  of  intersection  of  the  sloping  surface  and  the  vertical 
plane. 

8.  A  square  chimney  shaft  of  3  ft.  side  penetrates  a  roof  surface 
which  is  inclined  at  30°.  One  diagonal  of  tlie  shaft  is  parallel  to 
the  ridge.     Determine  the  shape  and  size  of  the  hole  in  the  roof. 

9.  The  H.T.  of  a  plane  is  inclined  at  60°  to  xy.  The  plane  is 
inclined  to  the  h.j».  at  45°.  Determine  the  vertical  trace,  and 
convert  the  plane  into  a  simple  inclined  plane. 

10.  The  traces  of  a  plane  are  parallel  to  xy.  Assuming  the  v.T. 
to  be  2  in.  above  a:y,  and  the  inclination  of  the  plane  to  be  30°  to 
the  II.P.,  determine  the  distance  of  tiie  ii.T.  from  xy. 


84        A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

11.  Draw  the  plan  and  elevation  of  a  hexagonal  prism  of  1|  in. 
edge  at  ends,  and  3  in.  axis,  when  the  axis  is  horizontal  but  inclined 
to  the  plane  of  elevation  at  40**.  Make  the  section  of  this  prism, 
when  cut  by  a  plane,  parallel  to  the  plane  of  elevation.  (C.  and  G. 
Prel.,  1898.) 

12.  A  hexagon  1^  in.  side  is  the  base  of  a  pyramid,  the  axis  of 
which  is  3  in.  in  height.  Draw  the  plan  and  elevation,  also  a 
section  parallel  to  the  axis  and  i  inch  from  it.  (C.  and  G.  Prel., 
1904.) 

13.  Draw  the  plan  and  elevation  of  a  right  hexagonal  pyramid, 
axis  4  in.  in  length  and  base  of  3  in.  side ;  also  draw  the  section  cut 
by  a  plane  passing  through  one  of  the  sides  of  the  base,  and  inclined 
at  60*'  to  the  axis.     (C.  and  G.  Prel.,  1901.) 

14.  Show  by  sketches,  the  manner  in  which  the  several  conic 
sections  are  obtained  from  a  cone.  Give  rules  for  approximately 
setting  out  an  ellipse.     (C.  and  G.  Prel. ,  1897. ) 

15.  Construct  an  ellipse,  having  its  major  and  minor  axes  3  in. 
and  1^  in.  long  respectively.     (C.  and  G.  Prel.,  1903.) 

16.  Draw  the  plan  and  elevation  of  a  cone.  The  diameter  of  the 
base  is  to  be  3  in.,  the  length  of  the  axis  4}  in.  Make  a  section 
parallel  to  the  axis,  and  a  section  which  is  an  ellipse,  whose  major 
axis  is  2^  in.  long.     (C.  and  G.  Prel.,  1902.) 


CHAPTER   IV. 

MENSURATION  OF  CARPENTRY  AND  JOINERY. 

Calculations. — It  is  constantly  necessary  for  the  carpenter 
and  joiner  to  make  calculations  from  the  given  dimensions  of 
the  sizes  of  the  materials  used,  the  areas  of  surfaces,  and  the 
volumes,  or  cubical  contents,  of  solids.  Although  most  of 
the  methods  used  involve  only  an  elementary  knowledge 
of  arithmetic,  it  will  be  advisable  to  work  out  in  full  a 
few  typical  examples  which  are  constantly  occurring  in 
practical   work. 

Units  of  lenfirth. — The  British  system  of  measurement  is  in 
yards,  feet,  inches,  and  sub-divisions  of  the  inch.  These  sub- 
divisions may  be  given  in  decimals  or  in  duo-decimals.  In  the 
decimal  system  the  unit  is  either  multiplied  or  divided  by  tens, 
and  the  working  of  such  calculations  is  easily  accomplished  by 
the  use  of  the  decimal  point.  Duo-decimal  measurement  is 
expressed  in  feet,  inches,  and  lines,  the  ratio  of  increase  or 
decrease  being  in  twelfths. 

In  most  continental  countries  the  metric  system  is  in  general 
use.  This  system  is  gradually  increasing  in  favour  in  our  own 
country.  In  the  metric  system  the  unit  of  length  is  the  metre, 
approximately  equal  to  39*37  inches.  This  unit  is  divided  into 
ten  decimetres,  the  decimetre  is  divided  into  ten  centimetres, 
and  the  centimetre  is  divided  into  ten  millimetres. 
The  multiples  of  the  metre  are  : 

10  Metres  =  1  Dekametre  =       393-7  inches  =       32'  9" 

lODekametres  ==  1  Hectometre  =  3937  inches  =  328'  V 
10  Hectometres  =  1  Kilometre  =  39370  inches  =  3280' 10" 
10  Kilometres    =  1  M7riaiMefcre= 3.93700    inc\ies=S^ftOft'   Al'. 


86 


A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


The  sub-divisions  of  the  iiieti*e  are  : 

1  inillimetre=  0*03937    inches 
10  millimeties=  1  centimetre  =  0*3937      inches 
10  centimetres  =  1  decimetre  =  3*937        inches 
10  decimetres  =  1  metre         =39*37         inches  3'  SJ". 
It  is  frequently  found  necessary  to  convert  the  measurements 
of  one  system  to  equivalent  distances  in  the  other.     This  is  done 
as  follows  : 

Example  1. — How  many  millimetres  (mm.)  are  there  in  1 2  inches? 
In  39*37  inches  there  are  1000  mm. :  in  12  inches  there  are : 

1000x12 


39*37 


=304*8  mm. 


Example  2. —  What  is  the  metric  eq\iivalent  of\Q  inches? 
1000x16 


39*37 


=  406-4  nim.  =  40*64  cm.  =  4*064  dcm.=0-4064  metre. 


The  calculations  to  be  made  will  include  the  use  of  linear  or 
length  measure,  square  or  surface  measure,  and  cubic  or  solid 
measure. 

LoNQ  Measure.  Square  Measure. 

12  inches  =  1  foot.      (12  x  12)  =  144  square  inches  =  1  square  foot. 
3  feet     =  1  yard.       (3x3)=     9  square  feet     =  1  square  yard. 

Cubic  Measure. 
(12x12x12)  =  1728  Cubic  inches  =  l  Cubic  foot. 
(3x3x3)=     27  Cubic  feet     =  1  Cubic  yard. 
In  the  metric  system  10  decimetres  =  1  metre  : 

1 0  X  1 0  =  1 00    square  dcm.  =  1  square  metre. 
1 0  X  10  X  10  =  1000  cubic  dcm.    =  1  cubic  metre. 
British  and  Metric  Units.— Figs.   149  to   152  show  the 


.|CM 


-•> 


^.  -  . 


■I  Inch- 


Kit  J.  149. 


Fir..  150. 


Fi(>.  151. 


comparative    size   of    the   inch    and    the    centimetre    both    as 
regards  linear,  square,  and  cubic  measurement.     It  will  be  seen 


MENSUKATION  OF  CARPENTRY  AND  JOINERY,  87 


Fig.  152. 


that  the  inch  is  just  over  two  and  a  half  (2*54)  times  as  long 

as   the   centimetre.     In    square   measure,  which   involves   the 

multiplication  of  a  length  by  a  breadth,  the  area  of  the  square 

inch  is  6*45  times  the  area 

of    the   square  centimetre; 

while  in  cubic  measurement 

there  are  16*38  cubic  centi- 
metres in  a  cubic  inch. 
A  consideration  of   Fig. 

153  will  serve  to  illustrate 

further    the    difference 

between,  linear,  square,  and 

cubic  measurement.     First, 

it  must  be  noticed  that  every 

solid  has  three  dimensions, 

namely  length  (in  this  ex- 
ample  24   inches),  breadth 

(1 2"),  and  thickness  (6").    To 

obtain    the    area    (surface 

measure)    of    one    of    the 

largest  faces,  multiply  the  length  by  the  breadth, 
i.e.  24  X  12  =  288  sq.  inches,  or  2  sq.  feet. 

The  area  of  one  of  the  edges  is  obtained  by  multiplying  the 

length  by  the  thickness — 24x6  =  144  sq.  inches,  or  1  sq.  foot. 

The  cubic  content  is 
obtained  by  multiplying 
the  three  dimensions 
together  thus  : 
24xl2x6=1728cub.ins. 
or  if  the  measurements 
are  in  feet,  the  cubic 
content  is 

2x1x^  =  1  cub.  foot. 
Care  must  be  taken  to 
have    all   the    measure- 
ments in  the  same  units 
— either  feet  or  inches. 
When  making  calculations  it  is  always  advisable  to  take  a 

mental  survey  of  what  is  required  and  try  to  obtain  an  appioxi- 

mate  result  which  may  serve  as  a  guide  and  possibly  prevent 

errors  in  the  subsequent  calculation. 


Fio.  153. 


88         A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

Squares  and  Square  Boot. — The  square  of  a  number  is 
obtained  by  multiplying  the  number  by  itself ;  thus  : 

22=2x2=4.     102  =  10x10=100.     242=24x24=576. 

The  square  root  of  a  number  (indicated  by  the  sign  ^~)  is  that 

quantity  which  when  multiplied  by  itself  is  equal  to  the  number ; 

thusV36=6;  V64  =  8. 

The  rule  for  finding  the  square  root  of  a  number  is  as  follows: 

Example. — To  find  the  square  root  of  529. — Mark  off  the 

number  529  into  periods  of  two  figures  as  indicated,  beginning 

^^^  with  the  units  figure.    The  nearest  square  to  5  is 

2)629(23      4,  the  square  root  of  which  is  2.     Put  2  in  the 

A answers  place.     Square  2,  place  the  result  4  under 

43   129  5  and  subtract.     Bring  down  the  next  period  29  ; 

^^^  place  the  double  of  2  in  the  left  column.     Divide 

all  except  the  right-hand  figure  of  129  by  4,  this 
gives  3.  Place  3  in  the  answer  place  and -also  to  the  right  of  4 
Multiply  43  by  3  and  place  the  result  129  under  129  and  subtract. 
As  there  is  no  remainder  the  work  is  completed  and  23  is  the 
square  root  of  529.  Test  this  by  multiplying  23  by  23,  the  result 
is  529. 

A  knowledge  of  square  root  as  well  as  of  the  following 
theorem  is  very  necessary  to  a  successful  working  of  a  large 
number  of  the  questions  to  be  considered.  In  a  right  angled 
triangle  the  square  on  the  side  {the  hypotenuse)  opposite  the  right 
angle  is  equal  in  area  to  the  sum  of  the  squares  on  the  sides  con- 

taining  the  right  angle.    [Euclid  1. 47.] 
Thus,  in  Fig.  154,  which  is  a  right 
angled  triangle. 

Assuming  the  sides  to  be  5",  4",  and  3" 
long  respectively,  then 

5x5  =  (4x4)  +  (3x3), 
Fio.  154.  25  =  1 6  +  9. 

This  example  and  the  proportions  of  the  sides  of  the  triangle  are 
of  some  importance,  since  by  an  application  of  the  proportions 
in  it  the  setting  out  of  right  angles  can  be  easily  and  accurately 
determined  or  tested  without  the  aid  of  special  appliances. 

Example  1 . —  What  is  the  length  of  the  diagonal  of  a  rectangular 
room  whose  sides  are  12'  and  9'  long  respectively  ? 

The  length  of  the  required  diagonal  is  the  square  root  of  the 


MENSURATION  OF  CARPENTRY  AND  JOINERY.     «9 

sum  of  the  squares  of  the  lengths  of  two  adjacent  sides  of  the 
rectangle.  As  the  lengths  of  the  sides  are  12'  and  9'  respectively, 
that  of  the  diagonal  is  : 

\/(l2xl2)-i-(9x9)  =  v/l44  +  81=\/225  =  15  feet. 

Example  2. —  What  is  the  length  of  the  diagonal  of  a  square 
of  8  feet  side  ? 

As  the  two  sides  are  at  right  angles  to  each  other  it  will  be 
necessary  to  square  them  both,  add  the  result,  and  extract  the 
square  root.     Then  the  length  of  the  diagonal  is 

slSH~^ = V64  +  64 = \/T28  =  11-31  feet. 

Example  3. — The  diagonal  of  a  square  room  is  18',  what  is  the 
length  of  side  ? 

Let  X  equal  the  length  of  the  required  side  ;  then 

2^  =  182 ;     /.   ^  =  \/3|i;=^/i62  =  12-72  feet  =  12'  8§^ 

Example  4. —  What  is  the  perpe^i- 
dicular^  height  of  an  equilateral 
triangle  of  12  feet  side  ?  j 

The  height  of  the  triangle  (Fig.                  / 
155)  is  obtained  by  squaring  the  side                / 
AB  ;    squaring  BD   (half  the  base              / 
BC)  ;  subtracting  BD'^  from  AB^  and           / 
extracting  the  square  root.  g  Z 

Let  X  equal  the  required  height  of  ^  ^ 

the  triangle  then  : 

:F2=(^^-i5/)2)=(12xl2)-(6x6)=144-36=108 

.-.   X  =  ^108  =  10-39  feet  =  10'  41". 

Example  5. — A  building  24  feet  wide  {outside  measurement)  is 
roofed  to  slope  both  ways.  The  ridge^  which  is  in  the  centre^  is  8 
feet  above  the  level  of  the  walls.  What  will  be  the  length  of  the 
common  rafters? 

This  example  is  solved  by  finding  the  length  of  the  hypotenuse 
of  a  right-angled  triangle,  the  known  sides  being  the  height  of 
the  ridge  (8'),  and  half  the  width  of  the  building  (12'). 

Let  X  equal  the  required  length  of  the  rafters,  then 

^=^/(8x8)  +  (12xl2)  =  \/64  +  144=^/208 
==14-42feet  =  14'5o\". 


90        A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

Example  6. — An  inclined  tpur  against  a  vertical  post  is  20  feet 
long.  Tike  loiter  end  rests  upon  the  ground  1 2  feet  distant  from  the 
foot  of  the  post.  At  what  height  from  the  ground  is  the  upper  end 
of  the  .*pur  f 

Let  X  be  the  height  required,  then  : 

xW2()«-T2«=^^(20x^)-(12xl2)=\^400-144=^/256 
x=>/^266=16feet 

ABEAS. 

Sqnare  and  Bectangnlar  Figures. — The  areas  of  these  figures 
.ire  found  by  multiplying  the  length  by  the  breadth. 

Example  1.— Let  A  BCD  (Fig.  156)  be  a  rectangular  surface,  a 
floor  for  example,  the  length  and  breadth  of  which  are  respec- 
A  a|      tively  18'  and  8'.    As 

18x8  =  144, 

the  area  of  the  room  is  144 
square  feet. 

If  the  room  were  square 
and  of  the  same  area,  it 
would  be  necessary  to  find 
the  number  which  multiplied 
by  itself  equals  144,  that  ia  12.  Therefore  a  room  12'x  12'  will 
have  the  same  area  as  a  room  18'  x  8',  namely  144  square  feet. 

Example  2. — A  square  room  has  an  area  of  1296  sq.feet;  what 
is  the  length  of  the  side  of  the  room  ? 

Find  the  square  root  of  1296.  This  is  found  to  be  36.  There- 
fore the  length  of  the  side  of  the  room  is  36  feet. 

Example  3. — A  rectangular  room  is  14'  6"  long  and  12' 9"  wide, 
what  area  is  the  floor  surface? 

This  example,  which  involves  fractions  of  the  foot  easily 
expressed  in  both  measurements,  may  be  worked  in  either 
fractions  and  decimals. 

In  Fractions  :  In  Decimals  : 

14'6"  =  14i'.  14' 6"  =  14-5'. 

12' 9"  =  121'.  12' 9"  =  12-75'. 

Area  =14^x121  *  145  x  1275  =  184-875  sq.  ft. 

29     51  "29x51     1479     ^^,.         -^ 
=  -x-=-g-  =  -^  =  184>- sq.ft. 

The  area  is  184^  sq.  ft.  or  184  sq.  ft.  126  sq.  in. 


Fia.  156. 


AREAS.  91 

Example  4. —  What  is  the  length  of  one  side  of  a  square  roomy 
the  floor  of  which  contains  1000  sq,  feet  area? 

The  square  root  of  1000  is  31*622,  therefore  this  is  the  length 
in  feet  of  the  side  of  the  room. 

31-622  feet =31' 7  v. 

For  practical  purposes  it  is  seldom  necessary  to  work  out  these 
results  beyond  the  second  place  of  decimals. 

Example  5. —  What  is  the  length  in  metres  of  the  side  of  a  square 
room  of  50  sqiiare  metres  area  f 

V50=     7*071  metres =7  m.  0  dcm.  7  cm.  1  mm. 
=  70*71  dcm. 
=  707*1  cm. 
=  7071  mm. 

Example  6. —  What  is  the  length  of  the  side  of  the  room  in  Ex.  5 
in  feet? 

1  metre  =  39*37  inches =^r^-  feet. 

^^-1        *  39*37x7071     278*385     „_,„,„ 

7*0  / 1  metres = r-- = — r^r — = 23  2 V . 

12  12  ** 

Example  7. — A  flat  roof  20'  hy  12'  has  in  the  centre  a  raised 
lantern  light  the  outside  dimensions  of  which  are  10'  hy  6'.  How 
wxiny  sq.  feet  of  sqiiare-edged  boarding  loill  he  required  to  cover 
the  flat  roof  surf  ace  ? 

Area  of  the  whole  surface  =  20  x  12=240  sq.  feet. 
Deduct  for  lantern  light       10x6  =60.       „ 
Quantity  of  boarding  required 

=  240-60  =  180  sq.  feet. 

Triangles. --The  area  of  a  triangle  can  be  obtained  by  multi- 
plying the  length  of  the  base  by  half  the  perpendicular  height, 

that  is,                       ,          perpendicular  heis^ht 
'  area  =  base  x  ^ — ^— . 

The  shape  of  the  triangle  does  not  affect  the  result,  as  all 
triangles  on  the  same  base  and  between  the  same  parallels  are 
equal  in  area. 

Tlie  area  of  a  triangle  can  also  be  detei'iuined  by  the  following 
furinula  :  v«(«  —  «)(« - />)(*•  - r')  =  aiea  of  triangle,  when 

«  =  half  the  perimeter,  and 

«,  6,  c,  care  the  lengths  of  the  side^  of  the  trianiAe. 


92        A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

Example.-- 7b  ^wci?  the  area  of  a  triangle  the  sides  of  which  are 
5",  6",  and  7"  long  respectively. 

•Jsis-  a){s - h)(s^c)  =  \/9(9-5)(9-6)(9-7) = \/9x4x3x2 

=\/216  =  14'7  sq.  inches  nearly. 

Graphical  Solutions. — Many  examples  in  the  determination 
of  the  areas  and  sides  of  triangles  can  be  more  easily  solved  by 
graphic  construction  than  by  arithmetical  methods.  Graphic 
methods  are  also  to  be  employed  by  preference  in  cases  where 
the  arithmetic  is  laborious.  In  the  following  examples  only 
the  simpler  ones  are  worked  by  arithmetic. 

Example  1. — A  triangle  has  a  base  of  8'  and  a  perpendicular 
height  of  10'.      What  is  its  area  f 

Area= — ^ —  =40  sq.  feet. 

Example  2. —  What  is  the  area  of  an  equilateral  triangle  of  12' 

edge ?  

Area  =  ^s{s  -  a){s  —  b){s  —  c) 

=\/l8(18  - 12)(18  - 12)(18  - 12) 

=\/r8  X  6  X  6  X  6=\/3888=62-35  sq.  feet. 

Example  3. — A  triangle  has  a  perpendicular  height  of  50  cm. 
and  an  area  of  30  sq.  dcm.     What  is  the  length  of  the  base  of 

the  triangle  ?  area  x  2 

Base  = 


perpen.  height 

As  the  area  is  in  decimetres  and  the  height  is  in  centimetres 

^,     ,  30x100x2     _„  ,^, 

the  base  = rpi =120  cm.  =  12  dcm. 

50 

Example  4. — A  triangle  with  a  base  16  dcm.  in  length  has  an 

area  of  12  sq.  feet.     Find  the  height  and  the  length  of  the  base  in 

feet,  the  perpendicular  height  of  the  triangle  in  cm.,  and  also  the 

area  in  sq.  dcm. 

As  1  dcm.  =  3*937  inches,  the  length  of  the  base  of  the  triangle 

will  be  16x3-937  =  62-992  inches  =  5*25  feet ; 

the  height  of  the  triangle  in  feet 

_       area  X  2       _12x2^      „. 

"length  of  base"  5-25  ' 

4*57  X  12 
the  height  in  dcm.  =       ^^    =  13-93  =  139*3  cm. ; 

16  X  13*93 
the  area  of  the  triangle  in  sq.  dcm.  = ^ —  =  1 11*44. 


AREAS. 


93 


Triangles  and  parallelograms  on  the  same  base  and  between  the 
same  parallels  are  equal  in  area.  Thus,  in  Fig.  157  the  triangles 
ABC^  DBCy  and  EBC,  all  being  upon  the  same  base  EC 
and  between  the  same  parallels  BC  and  DE,  are  equal  in 
area.  As  previously  explained,  the  area  of  a  square  or  rect- 
angular figure  may  be  obtained  by  multiplying  the  length  by 


FlQ.  158. 


the  breadth.  The  area  of  a  triangle  is  equal  to  a  rectangle 
upon  the  same  base  and  of  half  the  altitude,  or,  what  is  the 
same  thing,  to  a  rectangle  having  half  the  base  and  the  same 
altitude.      The   rectangle   BCDE  (Fig.    158)   is  equal   in    area 

AF 


to  the  triangle  ABC  when  the  height  BE  is  equal  to 


By 


drawing  to  scale  any  triangle  the  length  of  the  sides  of  which 
are  given,  the  area  can  thus  be  easily  obtained. 


Pio.  169. 

Example  1. — To  find  the  area  of  the  parallelogram  A  BCD. 
(Fig.  159). 

Multiply  the  length  by  the  breadth.  The  fact  that  the  angles 
are  not  right  angles  does  not  affect  the  result.  Care  must  how- 
ever be  taken  to  measure  the  breadth  at  right  angles  to  the 
long  sides.  As  the  length  is  10'  and  the  breadth  is  6'  the  area 
is  10x6=60  sq.  feet. 


94         A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


Fig.  160. 


Example  2. — Detennine  a  square  eqttal  in  area  to  a  given 
rectangle. 

Let  A  BCD  (Fig.  160)  Le  tlie  given  rectangle.     Produce  BC 

and  make  CE  equal  in 
length  to  BC.  Bisect 
DEa,t  0  and  with  OD 
as  radius  and  0  as 
centre  draw  the  senn- 
circle  BFE.  Produce 
CB  to  intersect  the 
semicircle  at  F.  Then 
CF  is  the  length  of  the 
side  of  the  square, 
because  CF  multiplied 
by  itself  is  equal  to  DCxBC  This  example  shows  how  square 
root  can  be  worked  graphically. 

Areas  of  Polygons  and  Irregular  Figures. — An  easy  way  of 
determining  the  areas  of  polygons  and  of  nregular  figures 
which  are  bounded  by  straight  lines  is  to  sub-divide  them  into 
triangles,  find  the  areas  of  these  separately,  and  then  add  the 
results  together.  This  can  be  done  either  by  arithmetic  or 
gi^phically,  the  latter  by  preference. 

A  rule  applicable  for  finding  the  area  of  any  regrular  polygon 
is  to  multiply  half  the  perimeter  by  the  perpendicular  from  the 
centre  to  any  side.  (The  perimeter  is  the  sum  of  the  lengths 
of  the  lines  bounding  the  figure.) 

Example  1. — To  find  the  area  of  any  given  regular  polygon^ 
{e.g.  a  regular  hexagon  ofZ  side). 

(1)  Arithmetically. — A  regular  hexagon  consists  of  six  equal 
equilateral  triangles,  in  this  case  of  3'  side.  The  area  of  each 
triangle  is: 

^s{s  —  a){s  -b)(8-  c). 

Area  of  hexagon  =6  x  \/4-5(4-5  -  3)(4-5  - 3)(4-5  - 3), 

=  6x\/4*5x  1*5  X  1*5  X  1*5, 

=  6x\/l5-1875, 

=  6x3-897  =  23-38  sq.  feet. 

(2)  Graphically.— Let  A  BCBEF (Fig;.  1 61 )  be  the  given  hexagon 
drawn  to  scale.     The  area  of  this  figure  is  equal  in  area  to  the 


AREAS. 


95 


rectangle  AEHO^  since  the  triangle  AFE  is  deducted  from  the 

hexagon,  and  the  two  triangles  fiG^(7  and  (7/>Zr which  are  together 

equal    in    area    to  AFE  are 

added.       By    measuring    the 

sides    of    this    rectangle    and 

multiplying     them     together 

the    area    of    the  polygon  is 

obtained. 

Example  2. — To  find  the  area 
of  a  regular  pentagon  of  4'  side» 

This  is  one  of  those  ex- 
amples where  it  is  difficult  to 
apply  arithmetic  only  in  the 
solution  of  the  question.  By 
drawing  the  pentagon  to  scale, 
the  perpendicular  distance  from  any  side  to  the  centre  is  obtained 
easily.    Then  the  area  of  the  figure  is  obtained  by  multiplying 

the  — — X by  the  length  of  this  perpendicular  distance. 

Area  of  pentagon  =  P^""^^  ^  ^ ^(^.^j  x  276  =  27*6  sq.  ft. 

Example  3.     To  find  the  area  in  sq.  indies  of  a  regular  octagon 
of  6"  side. 

The  area  of  this  figure  may  be  obtained  by  drawing  it  to 
scale,  measuring  the  perpendicular  distance  from  any  one  side 
y'^s^  to  the  centre  point,  and  multi- 

plying this  by  half  the  perimeter 

sC ^ ^       of  the  figure. 

Another  method  is  to  find  the 


Fio.  161. 


H 

Pio.  162. 


square  which  contains  the  figure, 
find  its  area,  and  from  this  to 
deduct  the  area  of  a  smaller 
square  on  the  side  BC  (Fig.  162). 
This  smaller  square  is  equal  in 
area  to  the  sum  of  the  four 
triangular  corners  which  must 
be  deducted  from  the  large 
square  to  obtain  the  octagon. 
This  question  provides  a  good  arithmetical   example.     It  is 

first  necessary  to  find  the  length  of  side  of  the  large  sc\M^t^ 

which  encloses  the  figure. 


d6 


A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


To  find  the  length  of  the  side  of  a  square  whose  diagonal  is  6^. 
Let  jp=the  side  B2  in  the  figure,  then  2a^—B(P ; 

.-.   2^-2=6x6=36, 


a^=     4^  =  18, 


x==  \/l8  =  4*24  inches. 
The  length  of  side  of  the  large  square  is  therefore 

=  4-24  +  6  +  4-24 = 1 4*48". 


Area  of  the  large  square   - 
Area  of  small  square  which  must 

be  deducted  for  the  corners  is  6x6 

Leaves  the  area  of  the  octagon  equal  to 


=  14-48  X  14-48  =  209-67  sq.  in. 


36       sq.  in. 
173-67  sq.  in. 


Example  4. —  To  find  the  area  of  a  given  irregvlar  fi/gwre. 

Let  ABODE  (Fig.  163)  be  the  given  figure.  The  easiest  solu- 
tion is  to  work  it  graphically,  finding  a  rectangle  of  equal  area. 

This  is  done  by  an  application 
of  the  fact  that  triangles  on 
the  same  base  and  between 
the  same  parallels  are  equal 
in  area  (Fig.  157,  p.  93). 
Produce  AB  and  join  AD. 
Through  E  draw  EF  parallel 
to  DA  ;  then  the  triangles 
AFD  and  AED  are  equal, 
as  they  are  between  the  same 
"G  parallels  AD  and  EF  and  on 
the  same  base  AD.  Join  DB 
and  through  G  draw  CO 
parallel  to  DB.  Join  DG.  Then  DCB  and  DGB  being  on  the 
same  base  BD  and  between  the  same  parallels  BD  and  GC  are 
of  equal  area.  Thus,  the  triangle  FDG  is  equal  in  area  to  the 
pentagon  ABODE.    A  rectangle  whose  length  is  FG  and  height 

-^  gives  the  required  area. 

Generally  the  shape  of  the  figure  decides  the  method  which 
it  is  advisable  to  adopt  in  the  calculation  of  areas.  If  the 
surface  is  of  irregular  shape  with  straight  sides,  the  area  can  be 
obtained  by  sub-dividing  the  whole  space  into  rectangles  and 
triangles,  calculating  these  separately,  and  then  adding  them 
together. 


Fig.  163. 


AREAS. 


07 


Example  5. — To  jmd  the  number  of  square  yards  of  flooring 
required  to  cover  the  floor  of  the  room  (Fig.  164). 

Find  the  area  of  each  of  the  lettered  spaces  separately  and 
then  add  them  together. 


{• 


I5-6'- 


'     c     ^'  J  * 


13' 


Fio.  164. 

Area  of  space  A  =  15'  6"  x  13'  =  201^  sq.  ft. 

i?=  6       X   2  =   12 

^7=  5       X   3  =   15 

/>=  7       X    7  ==  49 


jj 


» 


J) 


total  area  =  277^  sq.  ft. 

Circles  and  other  Figures  bounded  by  Curved  Lines.— The 
radius  of  a  circle  is  equal  to  one  half  the  diameter,  and  the  length 
of  tlie  drcninference  is  obtained  by  multiplying  the  diameter  by 
3' 141 6,  which  is  approximately  3f,  This  number  is  represented 
by  the  Greek  letter  ir.  Thus,  the  radius  of  a  circle  of  3"  diameter 
is  1*5  inches,  and  the  circumference  is  3x3*1416  =  9*4248 
inches. 

Example  1. —  What  is  the  length  of  the  circumference  of  a  circle 
of  4  feet  radius  ? 
Circumference  =  2irr 

=  radiusx  2x3*1416 

4'  X  2  X  3*1416  =  25*1328  feet. 

Example  2. — The  girth  at  the  middle  of  the  length  of  the  trunk 
of  a  tree,  which  is  circular  in  section,  is  10  feet.  What  is  the 
radius?  10 


Eadius  = 


2i.aj, 


3-1416x2 

Q 


=  1*591  feet. 


98         A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

The  radius  of  any  segment  of  a  circle,  or  circular  arc,  may  be 

obtained  by  squaring  half  the 
chord,  dividing  by  the  rise, 
adding  the  rise,  and  dividing  by 
two  ;  or  (Fig.  165) 

Pio.165.  radiu8=^ ^ 


Example. —  What  is  the  radiibs  of  a  circle  the  chord  of  which  is 
8'  a7id  the  rise  in  the  centre  2'  ? 

(AB^^BD)+BD    \BdJ^  2    ^        2 


Eadiu8=  2  2  -       2       -     2 


2         2 

The  area  of  a  circle  is  obtained  by  squaring  the  radius  and 
multiplying  the  result  by  31416,  or,  area=7rr2. 

Example  1. —  What  is  the  area  of  a  circle  of  4'  diameter  F 

2  X  2  X  3141 6  =  12-566  feet. 

Example  2. — A  circle  has  an  area  of  3  square  feet^  what  is  the 
radius  ? 

Radius  =  A/--^— -=x/a9549=0-97  feet. 
V3'1416 

Example  3. — The  circumference  of  a  circle  is  12  inches.     What 

is  its  area  ? 

J..        X         12  ^.6  7rx62         62 

Diameter = —  ;     /.   radius  =  -  :     .-.   area  =  — :.— = ^r^rr,  ^ 
TT  tt'  ir^        3*1416 

=  11*4  sq.  inches. 

Example  4. —  What  is  the  area  of  a  semidrc^dar  surface  the 

radius  of  which  is  8  feet  ? 

The  area  is  half  that  of  a  circle  of  the  same  radius. 

.           7rr2     3-1416x8x8     ,^^^         .    ^ 
Area  =  —  = «    =  1 00-53  sq.  feet. 

Example  5. —  What  is  the  area  of  a  quadrant  (a  quarter  of  a 
circle)  the  radius  of  which  is  6  inches  ? 

Area  of  circle        =6  x  6  x  31416  =  36  x 31416. 

Area  of  quadrant^ =9x3*1416  =  28-27  sq.  inches. 


AREAS.  99 

Example  6. —  What  is  the  area  of  an  annutiLs  {ring)  the  larger 
diameter  of  which  is  10  feet  and  the  smaller  diameter  b  feet. 
Area  of  annulus=area  of  large  circle  — area  of  small  circle. 

=  [(5  X  5)  -  (2-5  X  2-5)]  x  3-1416 

=(25-6-25)x31416  =  18-75x3-1416=58-905  sq.  feet. 

Example  7. — One  side  of  the  interior , of  a  room  is  12  feet  long, 
and  10  feet  high,  and  contains  a  window-opening  with  a  setni- 
circular  head.  The  width  of  this  opening  is  4'  6",  and  the  total 
height  of  the  window  is  T  3".  What  is  the  exact  area  of  the  wall 
mrface  on  this  side  of  the  room. 

Area  of  the  side  of  the  room  =  12  x  10  =  120  sq.  feet. 

Area  of  rectangular  part  of  window  opening 

=  5x4-5  =  22-5sq.  ft. 

Area  of  semicircular  parti  _ (2*25)2  ^  3-1416 __ 
of  window  opening      / ""  2  ~ 


Total  area  of  window  opening  =30*5 

Required  area  of  wall  surface  120-30*5  =  89*5  sq.  feet. 

The  approximate  area  of  an  ellipse  (near  enough  for  all 
practical  purposes)  is  obtained  by  multiplying  the  product  of  the 
two  axes  by  0*7854 

Example  1. — An  ellipse  has  axes  0/  16  feet  and  10  feet.    Hoio 
nany  square  feet  does  it  contain  f 
Area  of  ellipse  =  16  x  10  x  0*7854= 125§  sq.  feet. 

Example  2. — The  inclined  roof  surface  on  one  side  of  a  hxdlding 
is  20  feet  long,  and  16  feet  ivide  measured  from  eaves  to  ridge.  In 
the  roof  surface  is  a  rectangular  skylight  b'  3"  long,  by  3'  3"  wide, 
and  also  a  circular  shaft  passes  through  it  which  requires  an 
dliptical  space  4'  by  3'.  What  is  the  area  of  the  roof  surface  to  be 
covered  allowing  for  these  voids  ? 

Total  area  of  roof  surface  =  20  x  16  =  320    sq.  ft. 

Rectangular  space  for  roof  light  =  525  x  3*25=  17*06  „ 

Bfliptical  space  for  circular  shaft  =  4  x  3  x  0*7864  =     9*42  „ 

Total  area  to  be  deducted  =  17-06 +  9*42=  26*48  „ 

.•.  Area  of  roof  surface  to  be  covered  =  320 -26*48  =  29352  „ 

To  measure  the  area  of  irregrular  surfaces  which  have  curved 
boundaries,  sub-divide  them  into  rectangles  or  triangles  of 
approximately  the  same  size,  find  the  areas  of  these,  and  add 
them  together. 


100       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


GUBIG  OB  SOLID  MEASURE. 

Cubic,  or  solid  measure,  is  involved  in  the  calculations  of 
quantities  of  timber,  stone,  etc.,  excavations  of  earth,  sizes  of 
rooms,  buildings,  and  in  any  questions  affecting  mass.  An 
illustration  of  the  difference  between  surface  and  solid  measure 
is  seen  by  considering  the  various  measurements  of  a  lead-lined 
wooden  cistern.  Such  a  cistern  is  usually  employed  to  hold 
water  or  other  liquid  substance,  and  the  size  will  be  regulated 
by  the  volume  required  to  be  stored.  It  may  be  that  there  are 
limitations  as  to  length,  or  breadth,  or  the  depth  of  such  a 
cistern,  any  of  which  will  affect  the  other  dimensions  in  obtain- 
ing the  required  capacity.  Suppose  the  cistern  to  be  10  feet 
long,  6  feet  wide,  and  3  feet  deep,  inside  measure.  The  cubic 
content  or  the  volume  of  water  it  will  hold  when  full  is 
obtained  by  multiplying  together  the  length,  the  breadth,  and 
the  thickness,  thus  10x6x3  =  180  cubic  feet.  On  the  other 
hand,  if  the  quantity  of  sheet  lead  required  for  lining  this 
cistern,  not  allowing  for  joints,  must  be  obtained,  it  is  necessary 
to  find  the  surface  measurement  of  the  inside. 
That  is  :  two  sides  each  10  feet  by  3  feet=  60  sq.  feet 
two  ends  each  6  feet  by  3  feet  =  36  „  „ 
one  bottom       10  feet  by  6  feet=  60  „      „ 

/.   Total  quantity  required  =  156  sq.  feet. 

The  amount  of  timber  required  for  the  above  cistern  can  be 
obtained  only  when  the  thickness  of  the  material,  and  the  kind 
of  joints  to  be  used  in  the  construction,  are  known. 

Mode  of  calculating  Timber.— In  the  buying  and  selling  of 
timber  the  calculations  of  quantity  are  governed  by  trade 
custom.  Logs,  balks,  and  heavy  beams  are  usually  estimated 
in  cubic  feet,  while  planks  and  boards  may  be  reckoned  by 
the  square  foot  of  specified  thickness,  or  lineal  foot  of  given 
width  and  thickness.  The  following  standards  are  in  general 
use  : 

A  Petersburg  standard  (which   is  the  one    chiefly  used  in 
timber  calculations)  of  timber  contains  165  cubic  feet. 
This  is  equivalent  to     660  square  feet  of  3"  thick, 

or  1980      „  „       r'     „ 

or    220      „    yards  of  1"     „ 


.^ 


CUBIC  OR  SOLID  MEASURE.  101 

A  London  standard,  which  is  equivalent  to  the  Dublin 
standard,  contains  270  cubic  feet, 

or  1080  square  feet  of  3"  thick, 
or  120  pieces  each  12'  long,  9"  wide,  and  3"  thick. 
A  load  of  sawn  or  hewn  timber  contains  50  cubic  feet. 
A  load  of  unhewn  „  „        40         „ 

A  square  of  flooring  contains  100  square  feet  or  10'  x  10'. 

Example  1. — A  square  halJc  of  timber  is  24  feet  Imig,  24  inches 
ividey  and  24  inches  thick.  How  many  cubic  feet  of  wood  does  it 
contain  ? 

Content  in  cubic  feet =24  x  2  x  2=96  cubic  feet. 

Example  2. —  What  ivill  be  the  price  of  a  balk  of  timber  ZOfeet 
loTig  by  16"  x  16"  a^  2s.  per  cubic  foot  ? 

Content  in  cubic  feet  =  30  x  1 J  x  1 J  =  30  x  J  x  J = J^gi^ = 53J. 
Price  at  2s.  per  cubic  foot  =  53 J  at  28.  =  £5.  6s.  8d. 

Example  3. — The  dimensio7is  of  the  different  scantlings  in  a 
king -post  roof  truss  are  a^  follows:  one  tie-beam^  22'xl2"x5"; 
two  principal  rafters  each  13'  x  6"  x  5"  ;  one  king -post  ^  T  x  8"  x  5"  ; 
two  struts  each  6'  x  3"  x  5".  How  many  cubic  feet  of  timber  does 
the  above  truss  contain  and  how  much  will  it  cost  at  2s.  2d. 
per  cubic  foot  ? 

Quantity  of  timber = 22' x  rx5"=22  square  feet  of  5"  thick. 

26'xi'x5"=13  „  „ 

7'x2'vr>"—  42 


12'xi'x5"=  3 


J)  jj 


42§x/^=  172  cubic  feet. 
Cost  at  2s.  2d.  per  cubic  foot  =  17|x2s.  2d.  =  £l.  18s.  6d. 

Example  4. — Hoio  many  floor  joists  eaxih  16'  x  9"  x  3"  are  there 
in  a  Petersburg  standard  ? 

Tlie  cubic  content  of  each  joist  16'  x  |'  x  J'=3  cubic  feet. 

Number  of  joists,  ^-3^  =  55. 

Example  5. — A  Petersburg  standard  of  \"  flooring  consists  of 
boards  all  of  which  are  18'  long  and  6"  wide.  What  is  the  number 
of  boards  ? 

Each  board  contains  18  x  ^  =  9  square  feet ; 

.*.   number  of  boards  =  1 980  -r-  9  =  220  boards. 

Each  board  has  an  area  oi  one  square  yard. 


102       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

Example  6. — A  ware/iouse  is  70'  long  arid  30'  wide,  inside 
measure,  and  three  storeys  high.  The  first  and  second  floors  are 
of  timber ;  wooden  hinders,  each  14"  deep  and  8"  thick  placed  10' 
apart  carry  T  hy  Z"  floor  joists  placed  at  15"  centres,  on  the  top  of 
which  rest  1^"  rebated  and  filleted  hoards  for  the  first  floor  ;  and 
\"  grooved  and  tongued  hoards  07i  the  second  floor,  Calcidate  the 
quantity  and  the  cost  of  the  material  required  for  these  floors, 
assuming  pitch  pine  for  the  heams  at  \s.  9d.  per  cubic  foot,  and 
white  deal  for  the  joists  and  floor  hoards  at  £11.  per  Petersburg 
standard, 

A  plan  of  one  of  these  floors  will  show  that  with  the  binders 
placed  10'  apart  each  floor  will  require  six  in  number,  and 
assuming  a  wall  hold  of  9"  at  each  end,  each  binder  will  require 
to  be  31'  6"  long.  The  plan  will  also  show  that  with  the  joists 
placed  at  15"  centres  24  rows  will  be  required,  the  joists  in  the 
end  bays  being  11'  long  to  allow  one  end  to  rest  on  the  end 
walls. 

Timber  required  : 

12  beams  each  31'  6"  x  14"  x  8" =294  cubic  feet  at  Is.  9d. 

=  £25.  14s.  6d. 
Floor  joists  in  both  floors  : 
10  bays  each  containing  24  joists  10'  long  x  7"  x  3" 

=  10  X  24  X  10=2400  lin.  ft. 

4  bays  each  containing  24  joists  11'  long  x  7"  x  3" 

=   4 X  24x11  =  1056  lin.  ft.; 

3456  lin.  ft. 

*^456  X  7 
.'.       ^.^^      =2016  square  feet  of  3"  stuff 

=  3  standards  4- 36  sq.  feet. 

3  standards  at  £11  =£33    0    0 
36  feet  at  4d.  =      0  12    0 

£33  12    0 

Area  of  lower  floor  =70  x  30  =  2100    square  feet. 

Add  oV  for  the  shrinkage!  _  q^, 

of  square-edged  boards/ "         " 

2187^     o^o  1  A 

—~  =  24,^5  sq.  yds. 

£11  per  standard  =  Is.  6d.  per  sq.  yd.  of  1|"  thick. 

.-.    243jig  sq.  yds.  of  Ij"  boards  at  Is.  6d.  =  £l8.  4s.  7d. 


CUBIC  OR  SOLID  MEASURE.  103 

Area  of  upper  floor  =  70'  x  30'  =  2100  sq.  feet. 

Add  ^\  for  loss  of  width)  _  ^ 

and  shrinkage  /  ~  ^  "       " 

2275 =252 J  sq.  yards. 

£11  per  standard  =  Is.  per  sq.  yd.  of  1"  thick. 

.-.   2527- at  Is.  =  £12.  12.  9d. 

Summary:  Cost  of  beams  =£25  14  6 

„       joists  =    33  12  0 

„       1  J"  boards  =    18    4  7 

„       1"  boards  =    12  12  9 

Total      £90    3  10 

Prism  and  Gylinder. — The  content  of  a  prism  or  a  cylinder 
is  obtained  by  multiplying  the  area  of  the  base  by  the  length. 

Example  1. — A  roughly  hewn  trunk  of  a  tree  is  of  octagonal 
shape.  The  length  is  30  feet  and  the  length  of  side  of  the  octagon 
is  12".      What  number  of  cubic  feet  does  it  contain  F 

Firat  obtain  the  area  of  the  octagon  by  the  method  explained 
on  p.  95,  Ex.  3.  This  gives  the  side  of  a  square  containing  the 
octagon  as  29"  long,  and  the  area  of  the  octagon  as  4f  square  feet. 

Cubic  content  of  the  balk  =  4|  x  30= 145  cubic  feet. 

Example  2. — The  hewn  trunk  of  a  tree,  octagonal  in  section,  is 
3'  across  (from  side  to  side),  and  18'  long.  Find  the  number  of 
square  feet  of  3"  stuff  it  will  yield. 

It  will  be  necessary  first  to  find  the  length  of  the  side  of  an 
octagon  in  a  square  of  3'  side,  Ex.  3,  p.  95. 

This  gives  a  length  of  side  of  octagon  as  1*24  feet. 

The  area  of  the  octagon  is  7*45  square  feet. 

The  cubic  content  of  the  balk  =  7*45  x  18  =  134*1  cubic  feet, 
and  it  will  yield  134*1x4  =  536*4  square  feet  of  3"  stuif  if  no 
allowance  is  made  for  the  waste,  inevitable  in  such  a  polygonal 
section. 

Example  3. — A  balk  of  timber  which  is  square  in  section  is 
27  feet  long,  and  contains  48  cubic  feet.  What  is  the  size  of  the 
section  ? 

Area  of  the  end  in  square  feet  =  — =-^  ; 

.'.    length  of  side  =  —r=-  =  -  =  1 1  feet. 


104       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

Example  4. — Find  the  cvhic  content  of  a  circular  tank  10'  deep 
and  8'  in  diameter. 

Area  of  en(i=4  x  4  x  3*1416 =60*265  square  feet. 

Cubic  content  of  tank =60*266  x  10=602*65  cubic  feet. 

When  measuring  and  calculating  the  contents  of  balks  of 
timber  that  are  smaller  at  one  end  than  the  other,  with  a 
gradual  taper,  the  usual  practice  is  to  take  a  mean  of  the  breadth 
and  the  thickness,  and  multiply  together  this  and  the  length. 
This  result  does  not,  however,  give  the  exact  content,  but  it  is 
considered  sufficiently  near  for  all  practical  pui*poses. 

Example  1. — A  rectangular  balk  of  timber  is  26'  6"  long^ 
18"  by  16"  at  one  end,  and  14"  by  12"  at  the  other.  What  number 
of  cubic  feet  does  it  contain? 

Mean  breadth,     i?±li=^=16"=lj', 


Mean  thickness,   — - — = — = 1 4"  =  1  J' ; 


2 

28 
2 


.*.   26Jx  1 J  X  1  J=  2" X -  X -=1^  =  41|  cubic  feet. 

Example  2. — The  trunk  of  a  tree  30'  long  is  2'  6"  in  diameter 
at  one  end  and  V  6"  at  the  other.  How  many  cubic  feet  does  it 
contain  ? 

Mean  diameter,  ?5j+i^=24"=2'. 

Area  of  section  =  l  x  1  x  3*1416=3*1416  square  feet. 
Cubic  content    =    3*1416  x  30'  =  94*248  cubic  feet. 

Pyramid  and  Cone. — The  cubic  content  of  a  pyramid  or 
cone  is  obtained  by  dividing  the  area  of  the  base  by  one- third 
of  the  vertical  height,  i.e. 

.     ^     area  of  base  x  height 
content  = ^ — • 

Example  1. — An  equilateral -triangtdar-ba^sed  pyramid  of  6" 
edge  is  9"  high.     How  many  cubic  inches  does  it  contain? 
Area  of  base 

=>/s{s  -  a){s  -  b)(s  -  c)  - \^9  X  3x3x3  =\^243=  15*58 sq. ins. ; 
.*.   content  =  —    -     =46*74  cubic  inches. 


CUBIC  OR  SOLID  MEASURE.  105 

Example  2. — A  hexagonal  pyramid  of  ^  side  w  10'  high.     Cal- 
culate the  cubic  conte7it. 

Area  of  i  of  base  (an  equilateral  triangle  of  4'  side) 

= \f8{s-a){s-b){8-c) = >>/ 6x2x2x2 = ^48. 

Cubic  content  of  pyramid 
6xn/48x10 


3 


=  20  X  6-92  =  138-4  cubic  feet. 


[Example  3. — A  cone  has  a  base  12"  in  diameter  and  is  16"  high. 
What  is  the  cubic  content  / 

Area  of  base        =  6^  x  3-1416. 

^    ^     ^    .             6x6x3-1416x16    ^^oio      v.-    •     \. 
Content  of  cone  = ^ =  603*18  cubic  inches. 

Sphere. — To  find  the  cubic  content  of  a  sphere,  multiply 
the  cube  of  the  diameter  by  one-sixth  of  3*1416,  i.e. 

content =d^x  — ^  =  d^x  0*5236. 

u 

Example. —  What  is  the  cubic  content  of  a  sphere  of  6"  diameter? 

6  X  6  X  6  X  0*5236  =  113*09  cubic  inches. 

A  ready  and  accurate  method  of  finding  the  volume  or  cubic 
content  of  any  irregular  solid  of  small  size  is  totally  to  immerse 
the  solid  in  water,  using  for  the  purpose  a  receptacle,  the  capacity 
of  which  can  be  easily  measured.  The  volume  of  water  displaced 
will  be  equal  to  the  cubic  content  of  the  solid. 


Questions  on  Chapter  IV. 

1.  (a)  What  is  the  difference  between  the  English  and  the  metric 
system  of  measurement?  (fc)  What  is  the  metric  equivalent  of 
14  in.  ?    (C.  and  G.  Prel.,  1899.) 

2.  What  is  the  metric  equivalent  of  4  square  feet?  (C.  and  G. 
Prel..  1900.) 

3.  Determine  the  square  root  of  (a)  289 ;   (6)  3721  ;  (c)   69696. 

4.  Find  the  length  of  the  diagonal  of  a  square  of  12  ft.  side. 

5.  A  20  ft.  ladder  when  in  position  just  reaches  to  the  top  of  a 
19  feet  wall.  How  far  is  the  foot  of  the  ladder  from  the  foot  of  the 
wall? 

6.  Buildings  which  are  12  ft.,  16  ft.,  30  ft.,  and  43  ft.  wide 
(outside  measurement)  respectively  have  central  ridges  at  he\^\v\)^  oi 


106      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

4  ft.,  7  ft.,  14  ft.,  and  20  ft.    respectively  above  the  wall  levels. 
Find  in  each  case  the  length  of  the  common  rafters. 

7.  What  is  the  area  in  English  measurement  of  a  rectangle  5 
metres  long  and  3  metres  wide  ?     (C.  and  G.  Prel.,  1904.) 

8.  What  is  the  area  of  a  triangle  having  a  base  4  metres  long  and 
an  altitude  of  3  metres  ?    (C.  and  G.  Prel.,  1903.) 

9.  Describe  a  hexagon  within  a  circle  of  ^  of  an  inch  radius,  and 
find  how  many  feet  superficial  that  hexagon  would  represent  to  a 
scale  of  f  of  an  inch  to  1  ft.     (C.  and  G.  Prel.,  1902.) 

10.  A  room  is  25  ft.  6  in.  long,  13  ft.  6  in.  wide  at  one  end,  and 
18  ft.  4  in.  at  the  other.  What  is  its  area?  (C.  and  G.  Prel., 
1901.) 

11.  (a)  What  is  the  area  of  an  octagon  having  a  side  3  ft.  long? 
(b)  Make  an  irregular  pentagon,  and  construct  an  oblong  of  equal 
area.     (C.  and  G.  Prel.,  1899.) 

12.  Make  an  irregular  heptagon  and  reduce  the  same  to  an  oblong 
of  equal  area.     (C.  and  G.  Prel.,  1898.) 

13.  The  chord  of  a  circle  is  12  feet ;  the  rise  in  the  segment  is 
2  feet.  Find  the  radius  of  the  circle  by  figures.  (C.  and  G.  Prel. , 
1898.) 

14.  A  window  is  5  ft.  6  in.  wide,  and  the  head  rises  10  in.  from 
the  springing  line ;  the  curve  is  the  segment  of  a  circle.  Find  the 
length  of  the  radius  by  arithmetic.     (C.  and  G.  Prel.,  1901.) 

15.  It  is  required  to  make  a  cylindrical  framing  for  a  tank  which 
is  5  ft.  9  in.  in  diameter ;  the  framing  is  to  be  3  in.  from  the  tank 
and  7  feet  high.  Find  the  superficial  area  of  the  framing.  (C.  and 
G.  Prel.,  1902.) 

16.  What  is  tlie  cubic  content  of  a  balk  of  timber  4  ft.  square  at 
one  end,  and  2  ft.  6  in.  square  at  the  other  end,  and  10  ft.  long  ? 
(C.  andG.  Prel,  1900.) 

17.  A  balk  of  timber  is  20  feet  long,  15  inches  by  15  inches  at  one 
end,  and  12  inches  by  12  inches  at  the  other.  What  would  be  its 
price  at  2s.  per  foot  cube  ?     (C.  and  G.  Prel. ,  1897. ) 

18.  Find  the  cubical  content  of  a  hexagonal  prism  of  10  ft.  axis 
and  2  ft.  side.     (C.  and  G.  Prel.,  1901.) 

19.  What  is  the  cubic  content  of  a  hexagonal  prism  of  3  ft.  edge 
and  7  ft.  long?     (C.  and  G.  Prel.,  1899.) 

20.  What  is  the  cubical  content  of  half  a  regular  hexagonal 
pyramid  of  2  feet  edge  and  5  feet  high  ?    (C.  and  G.  Prel. ,  1 898. ) 


CHAPTER  V. 

TOOLS. 

General  Remarks. — The  tools  used  by  the  carpenter  and 
joiner  are  of  so  varied  a  character  that  a  special  consideration 
of  the  manner  of  using  them,  and  of  the  means  of  sharpening 
and  otherwise  keeping  them  in  order  is  necessary.  It  is  of  the 
greatest  importance,  as  all  experienced  craftsmen  know,  to  have 
tools  of  the  best  material,  and  to  use  them  with  the  greatest 
care,  so  that  they  can  be  relied  upon  for  durability  and  accuracy. 
All  edged  tools  should  be  of  evenly  tempered  steel,  so  that  they 
will  retain  for  a  reasonable  time  the  sharp  edge  required  for  use. 

Machinery  is  now  extensively  used  in  the  preparation  of  the 
timber  for  all  kinds  of  wood  work.  Besides  facilitating  working, 
this  renders  unnecessary  many  tools  and  appliances  which  were 
formerly  in  use. 

The  Training  of  the  Eye. — One  of  the  fii^t  objects  of  the 
intelligent  workman  should  be  to  train  his  eye  to  estimate 
dimensions  and  to  judge  whether  lines  are  straight  and  surfaces 
are  ti*uly  plane.  This  power  can  only  be  obtained  by  careful  and 
conscientious  practice. 

IffEASUBma  AND  TESTma  TOOLS. 

The  one-,  two-  and  three-foot  rule,  the  tape  or  chain  measure 
and  loooden  staves  or  rods  of  various  lengths,  are  the  usual  means 
by  which  measurements  are  made.  The  two-foot  rule  used  by 
the  wood- worker  generally  has  the  *  inches  sub-divided  into 
eighths  and  sixteenths.  In  work  of  large  dimensions,  carefully 
graduated  rods  (which  can  be  made  by  the  workman  himself) 
are  preferable  to  either  the  rule  or  tape  measure,  a^  \)y  \\i^\T 


108      A  MANUAL  OF  CARPENTRY  AND  .WffSRftV^" 


[ltd  are  obtained.     In  preparing 

^iigth,  it  is  liest  to  lay  two-foot 

i'iiIuh)  instead  of  using  only  oiie  nile 


Biiipiciyinent  mure  accurate  11 
such  a  ntd  of,  aay,  12  feet  ii 
rules  end  to  end  (us 
and  marking  with  a  pencil. 

The  Heasarement  of  Angles. — In  the  nieaHnrement  of 
angles,  or  irregular  smfaces,  ic  is  best  to  diviJe  the  surface  ii 
triftngles,  and  to  measure  the  aides  with  the  gmdaated  ■'oda 
mentioned  above. 

Testing  Tools. — Testing  tools  may  be  L-onsittered  nnder  two 
headings  :  those  used  in  tile  workshop  in  the  preparation  of  all. 
kinds  of  framing  and  other  beiiuhwork  ;  and  thoae  employed  n 
the  building  or  in  the  erection  of  any  structure.  Tlie  itraifffil- 
edge,  %mnding  itripi,  try-gqiutTe,  tlidiiig  hei'el,  marking  {/ange^ 
and  aompasiei  are  amonget  the  testiag  tools  used  in  the  bench 
work.  The  object  of  these  is  to  test  for  etraightneas,  size,  anil 
accuracy  the  material  employed. 

The  Btralgtit-edge. — The  best  material  for  short  atraighb 
edges  is  steel.  Wooden  straight-edges — made  fi-oni  stnklght> 
grained  wood  that  does  not  twist,  preferably  yellow  pine  or 
mahogany— ai*,  however,  generally  used. 


VlniUiig  Btrlps  a 


t  likely 


made  of  wood  that  ii 
They  a 
30  inches  long,  3  to  3  iuehw 
wide,  and  about  ^  Inuh  thick 
they  have  parallel  edges,  a 
are   used    when    "  tiueing-up' 
the   surface  of  the  wood  will 
the  plane. 

The  try-Bquare  (Fig.   166)   i 

u!<ed  for  testing  whether  bup 

faces    are   at   right    angles    t 

each  other,  as  well  as  for  dnif 

ing  "sfniare"  lines  O'.e.  at  light  angles)  for  w 

The  BliainB  Ksvel  (Fig.  107)  is  similar  in  character  to  the  tl 
square,  but  has  a  loose  blade.  It  is  used  when  surtaeea  or  lii 
not  at  i-ight  angles  to  each  other  are  rei|uired. 

Piffereut    kinds   of    gauges   are    used:    the   niarkiii?  j 
(Fig.  1(1R),  which  has  only  one  marking  point,  is  erjiployed  foi 
marking  llmw  pai"allel  to  the  edge  of  tlia  wooil  which  i 
worked.    A  morUi»-et.n8a(Fig.  1(19)  lias  two adjustalila  marking 
1  is  used  when  two  pamllel  lines  are  I'equired,  u 


Tir-squnn 


MRABtmmo  AWi>  TBsrnra  tools. 


the  setting  out  of  framing  with  mortise  and  tenon  joints.     Tlie 
cutting  Eaug*  has  a  cutting  blade  ijistead  of  a  marking  piiint. 


Pi.i.  nlT.-andii 

A  Uraml)  or  set  gauge  oa 
a,  repetition  of  siniilftr  1 

For  curved  work  the  oompaaBes 
a    i>»ii'  of   eomiMtaaos    fitted 
with  a  I'adial  arm  or  wing, 
of    use  to   connect   the   two 
11  prevent  their  slipping 


legBt- 

For   larger    work    a   pair  p,,, 

of    tranunsl   plna    is    needed 
(Fig.  171).     The  length  of  the  rod  used 
radius  of  the 


determined  by  the 
iiired.  A  simple  though  crude  substitute 
for  the  trammel  pins,  or  coiupasaes,  niny 
be  made  by  fixing  two  bi'ttdawls  at  the 
ends  of  a  rod  of  wood. 

The  testing  tools  used  by  the  carpenter 
For  fixing  framing  include  (in  addition 
to  those  above  described)'  the  ipirit  level, 
the  plvmA-rale,    plumbMite,    and    ckalk- 

The  Bidrit  level  (fig.  172)  consists  of  a 
small  sealed  glass  tube  containing  spirit. 
It  is  so  made  that  the  encloBOd  \ivi\ib\ft  lA 


HO      A  MANUAL  OF  CARPENTRY  ANTI  TOINBRt. 

air  occupieB  a  certain  poaition  only   when  the  instrumeDt  is 


placed  horizontally.     It  is  unuall;  ninunted  in  a  wooden  frame 
from  8  to  12  incibes  long,  and  is  generally  uued  in  conjunction 
■with     a     lung     parallel    ati'aight    edge,   W 
determine  whether  ajirfacea  are  level. 

The  pliunb-line  (Fig.  1T3)  ie  of  assistance 
to  determine  whether  walls  or  upright 
timbers  are  vertical.  It  consiat-t  of  a  string, 
at  the  lower  end  of  which  is  a  metal  weight, 
generally  lead,  tailed  a  plumb-bol)  (Fig.  \li)- 
For  convenience  in  practice,  the  string  r 
plumb-line  is  fastened  at  the  I'pper  end  to 
i"j  a  jiarallel  straight-edge  which  is  from  4 

■'■'  6  feet  long  and   3   tu  5  incliet  wide.     Thia 

sti-aigbl-edge  ia  marked  with  a  centra  liii' 
down  its  length,  and  has  a  hole  cut  near  th 
■i!  bottom,  in  which  the  bob  swings.   A  atraiglit- 

edge  so  fitted  is  called  a  plomb-rnle.  During 
the  fixing  of  cai-penters'  and  joinei's'  worlq,^ 
the  spirit  level,  straight-edge,  and  plumb- 
rule,  are  indispensable  testing  tools. 

The  chalked  line  is  useful  for  a  variety  o{' 
purposes.  When  a  lung  straight  Hue  f 
required  between  two  pointa  and  tbf 
straight-edge  ia  either 
not  available  or  is  too 
l\l'  -short,  a  straight  line  may 

be  obtained  by  chalking 
a  length  of  string,  fixing 
it  on  two  points,  pulling 
tight,   and    then    I'aising 
the    string  and    sharply    , 
letting   go.      The  line   ia 
'   akn  used  as  a  guide  and  aid  in  many  fixing 
o)io  rations. 
Oeoaietrical  Taata.— Many  aimj^a  gwWwrtrieal  principle* 


CUTTING  TOOLS. 

applied  in  workehnp  tests.  Ainiiiigst  tliefii  may  ha  meutiojied 
the  fiiliowing  : 

To  obtain  a  I'ight  angle,  it  is  nnly  neeeBsarj  to  draw  a  ti-iangle 
wliose  aides  am  in  the  proportion  of  3,  4,  and  6  (p.  88) ;  the 
angle  opposite  the  longest  side  is  a  right  angle. 

Again,  to  test  whether  a  piece  of  framing  is  truly  rectangular 
(or  in  workshop  phrase  "wjuare")  measure  the  lengths  of  the 
diagonals  ;  it  they  are  equal,  the  corners  are  right  angles. 


CUTTING  TOOLS. 
The  Saw. — It  is  very  necessary  that  the  blades  of  all  saws  be 
of  the  host  spring  steel,  of  uniform  hardneBB,  evenly  tempered, 
and  slightly  thinner  at  the  liack  tli^in  at  the  cutting  ei 


The  rip  saw,  used  for  cutting  with  the  grain,  that  is,  in  the 
direction  of  the  flbrea  of  the  wood  ;  the  croaa-cnt  saw,  for  cutting 
Mi'oss  the  grain  (at  right  angles  to  the  fibi'es)  |  and  the  panel 
law,  used  fen-  fine  woik,  are  all  of  the  shape  sliowii  in  Fig.  175. 
The  chief  diffei'ence  in  these  saws  lies  in  the  shape  and  sins  of 
the  teeth  on  the  cutting  edge. 


i 


The  rip  aaw,  usually  28"  long,  haa  the  teeth  points  from  0"'3 
to  0"4  ajiiirt,  or  about  8  teeth  to  3"  of  length  of  blade.  The 
Bbspe  of  the  tooth  is  shown  in  Fig.  1 7C.  Tlio  fi-ont  of  the  tooth 
!■  at  right  angles  to  the  cutting  edge  of  the  blade. 


ll>      A   MAXCAI.  <IF  CARI'KNTRV   AND  JOIN'ERY. 

The  croM-cnt  saw  is  usually  26"  long  ;  the  teeth  «re  smaller 
than  in  the  lip  )<aw — alwut  4  points  tu  the  iooh — the  front 
of  the  tooth  beiDg  inclined  at  an  angle  (from  65'  to  75')  to 


tlie  cnttinf;  edge,  a.i  xhown  in  Fig.  177.  Manr  modiications  in 
tlic  t-liHi)e  of  the  tnoth  of  the  civ>»i-i.'ut  saw  are  to  be  found,  euch 
as  the  p.-<j-(-K,ll,  (Fig.  178)  and  the  him-e-tootk  (Fig.  17»>  While 
the*f  teeth  may  produce  lietter  resulta,  and  cut  more  easily  in 
giift  wcMxl,  or  nhfn  utied  with  dry  timber,  the  ordinary  tooth 


rnav  l>e  considered  the  most  satisfactoij  for  all-round 

!l  saw  has  teeth  ninular  in  shape  to  those  of  the  eross- 
lut  niiK-h  siLialler  in  size,— from  6  to  8  poiata  to  the 

"  on  a  saw. — If  the  teeth  were  exactly  in  the  plane  of 
the  fiiitii.ii  or  •■I'iiiding''  sgainat  the  fibres  of 
would   n'lider   the  fi-ee  wording  of  the  saw  almont 

\i.  th-r  fiii-ti..ii  1«tween  the  »-ood  and  the  hiade,  the 
]e  ii:-t!i  !iiv  U-nt  siiirhtly  outwards,  alternately  to  one 
h'-ii  I.,  thf  iithri'.  «,  that  the  resalting  cut  is  wider 
l.ii.kntss  ■•{  th<-  blade  and  thus  gives  "clearance"  in 
Tlie  (I/.-tain.i;  wliitlv  the  poinu  ptojed  beyond  the 


CUTTING  TOOLS. 


113 


Fio.  180.— Saw-sot 


plane  of  the  blade  is  called  the  set.  Tlie  amount  of  set  required 
depends  upon  the  kind  of  material  to  be  operated  upon.  The 
bending  (setting)  is  done  either  by  means  of  a  nail  punch  and 
hammer  upon  a  block  of  hard-wood,  or  with  a  special  appliance 

named  a  "  saw-set."  Figs. 
180  and  181  show  two 
different  types  of  saw-set. 
The  rip  saw  requires 
less  set  than  the  cross- 
cut  saw  owing  to  the 
fibres  of  the  wood  being 
parallel  to  the  direction 
of  the  saw  cut,  while  the 
saw  used  in  the  work- 
shop— generally  upon  dry 
material — does  not  require  so  much  set  as  the  saw  employed 
by  the  carpenter  on  rough  and  sometimes  unseasoned  timber. 
The  less  set  there  is  on  the  saw — providing  it  will  clear — 
the  more  easily  the  saw  will  work.  The  set  on  each  side 
should  never  exceed  half  the  thickness,  so  that  at  the  most 
the  width  of  cut  is  not  more  than  twice  the  thickness  of  the 
blade. 

The  back  or  tenon  saw  (Fig.  182)  has  a  thinner  blade  than  the 
"hand"  saws  above   described.     The  blade  is  12"  to  16"  long. 


Fio.  181.— Saw-set. 


Fio.  182.— Tenon  Saw. 


Fio.  183.— Dovetail  Saw. 


3"  to  4"  wide,  has  about  ten  tooth-points  to  the  inch,  and 
has  the  back  edge  of  the  blade  stiffened  by  an  iron  or  brass  back, 
the  blade  being  thus  kept  rigid.  The  shape  of  the  tooth  is 
intermediate  between  that  of  the  rip  and  the  cross-cut  saws,  as 
the  tenon  saw  is  chiefly  used  for  fine  bench  work,  which  consists 
of  cutting  both  with  and  across  the  grain,  as  well  as  in  oblique 
directions. 

The  dovetaU  saw  (Fig.  183)  is  similar  to  the  tenon  saw,  but  is 
of  smaller  size,  and  "has  smaller  teeth.  Its  use  is  con^iv^d  \»q 
very  fine  work. 


114      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

The  bow  or  turning  saw  (Fig.  184)  has  a  thin  narrow  blade  held 
in  tension  by  a  wooden  frame  and  string.   It  is  used  for  cutting 
curved  surfaces,  its  narrow  blade  allowing   for  the  necessary 
turning  movements. 

The  compass  saw  (Fig.  185),  and  the  pad  saw  (Fig.  186),  have 
narrow  tapering  blades,  and  are  used  for  curved  surfaces  in 
circumstances  where  the  bow  saw  would  be  inapplicable. 


Fig.  185.— Compass  Saw. 


Fio.  184.— Bow  Saw. 


Fio.  186.— Pad  Saw  and  Handle. 


A  two-handled  saw  (Fig.  187)  for  cross-cutting  large  balks 
of  timber,  has  a  blade  from  4  to  7  feet  long,  5  to  8  inches  wide, 
with  large  teeth  of  shape  shown  in  Fig.  178. 

The  sharpening  of  saws. — Saws  for  hand  use  are  sharpened 
with  triangular  files  of  size  varying  with  the  size  of  the  teeth. 
The  ease  and  accuracy  with  which  a  saw  cuts  depends  largely 
upon  the  care  bestowed  on  the  setting  and  sharpening.     Some 


Fig.  187.— Two-handled  Cross-cut  Saw. 


experience  is  required  to  obtain  satisfactory  results.  All  the 
teeth  should  be  set  evenly,  be  of  uniform  size,  and  have  their 
points  in  a  perfectly  regular  line.  Rough  usage  of  saws  often 
causes  them  to  be  strained  or  buckled.  These  defects  can  be 
remedied  by  careful  hammering.  It  is  very  advisable,  however, 
that  this  process  be  deputed  to  the  expert,  as  any  unskilled 
attempt  may  ruin  the  tool. 

Planes. — A  plane  is  a  tool  which  derives  its  name  from  its  use 
in  the  preparation  of  plane  surfaces. 

A  wooden  plane  consists  of  the  following  parts — a  rectanfinilar 


CUTTING  TOOLS. 


116 


I  (generally  of  beecli  wood  by  reaBon  of  its  even  grain  and 
freedom  from  waiping  teudencj"),  the  face  or  sidf  of  wliich  must 
lie  aei'iirately  plane  (true).  Fixed  by  means  of  a  wedge,  and 
guided  by  the  stituk,  is  a  steel  eiittei' 
(plane-iron)  (t'ig.  1H8)  wLieli  jii'ojeotst 
slightly  beyond  the  sole,  and  makes  an 
angle  of  about45°  with  it.  When  planing 
cross-grained,  or  knotty  wood,  where  the 
fibres  of  the  wood  are  not  par;illel  to  the 
surface  being  operated  upon,  the  cuttei' 
has  a  tendency  to  "pluck  up"  the  giniTi, 
Thia  plucking  tendency  is  lessened  by  a 
guard  called  a.  back-  or  cap-Iron  wliich  is 
fixed,  by  means  of  a  screw,  to  the  face  of 
the  plane-iron.  Tlie  back-iron  is  the  same 
-width  aa  the  plane-iron,  and  capable  of  k.if.  i^s.-Linthig  iron 
adjtiatmeiit  to  different  distances  from  't  WiindcniiHni!. 
the  cutting  edge,  according  to  the  kind  of  work  and  the  character 
of  tlie  material.  By  setting  the  baek-ii'on  very  close  {e.g.  ^")  to 
the  cutting  edge,  the  plui:king  tendency  is  reduced  to  a  minimum. 
In  addition  to  this,  the  back  iron  stitieits  the  cutting  iron  and 
tliei-eby  lessens  vibration  or  "chattering";  it  also  serves  to 
break  the  shaving  as  it  enters  the  mouth  of  the  plane  and  thus 
prevents  choking. 

Inflanes  nsed  tor  working  hard  woud  it  is  advisable  to  have 
the  |tlane-ii'on  set  into  the  stock  at  a  steeper  pitch  than  for  soft 

t,  usually  about  5'i°  U<  the  sule  uf  the  plane, 
e  constant  wear  of  tlie  (Mile  of  a  wooden  phne  necesaitates 
Kit  occasional  trueing-up  of  its  surface.     The  result  of  this  is  to 
increase  the  aine   of  the  mouth,  and   produce   a   less   effective 
guiding  of  the  shavings  as  they  are  removed. 
^^'fhe  Jack  pfaas  (Fig.    1S9),   about  16"  limg,  the  te^iaSE 


116      A  MANUAL  OF  CARPENTRY   AND  JOINERY. 


(Fig.  IDO),  22"  Ions,  a'ld  t'i«  amoothing  plans  (Fig.  191),  9"  long 
are  tlie  usual   bencli   [ilanes.     Of  tlieae  the  jack  plane  is  used 


igliing  off;  tlie  trying  plane  for  trueing  up;  and  the 

used  for  finialiing  the  surface. 

The  accuracy  and  smoothness  of 
plaued  surfaces  depeud  upon  the  con- 
dition in  which  the  plane-iron  is  kept. 
Plane-irons  ai*  from  2"  to  2|"  wide,  the 
cutting  edge  is  ground  at  an  angle  of 
from  20°  to  2.")°  with  tlie  face,  and  the 
sharpening  angle  vai'ieB  from  25°  to  40°. 

„,j.  The  jack  plane-iron  should  have  the 

cutting  edge  slightly  convex,  as  shown 

res  It     f  th  9    s  that  the  ]  lane  takes  off 

th   ker        the  n  ddle  than  at  the  edges, 


and  the  corners  of  the  iron  do  not  plough  into  the  wood. 
The  irons  of  the  trying  and  smoothing  planes  should  be  square 
across,  excepting  at  the  corners,  which  niiwt  be  slightly  rounded 


CUnTNO  TOOLS. 


1171 


in  Vi^.  I!i3.  If  the  uuttiug  edge  of  these  is  curved  lut  in  tLe 
jiick  plane,  thu  liniBlied  plumed  surface  will  have  a  wavy  ap|)eai'- 
BiDce  and  ahow  in  aa  ubjectiuuable  manner  when  llie  surface  is 
painted  or  varnished. 

Iron  pUneB,  <ii'  uiirnbiniktiDU  iron  and  wooden  planes,  are  now 
supplementing  wooden  planes  to  a  large  extent.  The  advantage 
of  these  planes  over  wooden  ones  lies  in  the  tact  that  the  sole  of 
the  plane  does  not  weur,  and  therefore  does  not  get  "out  of 
truth  "  ;  the  mouth  of  the  plane  consequently  always  remains  the 
s&me  size.  Again,  in  these  planes  the  cutter  is  held  in  position 
by  means  of  either  a  screw  or  a  lever,  and  the  adjustment  is 
therefore  easier  and  n 


The  L'liltei's  of  iron  planes  are  thinner  than  those  used  in 
woodnu  planes  and  thus  a  saving  of  time  in  both  the  grinding 
and  sharpening  is  etfeoted  by  their  use. 

For  the  hest  class  of  work,  iron  planes  are  decidedly  better 
and  capable  of  givirjg  uiore  aceuiate  results  than  wooden  planes. 
iJisudvantagOfl  lie  in  tiie  fact  that  they  ara  heavier,  and  when 
used  in  the  uiuitifaiions  work  required  by  the  carpenter  when 
Hxing,  they  will  not  bi  " 
planes  are  subjected, 
typical  example  of  an  ir 

The  panel  plane  is  ii 
size    between    a    jack 
siiKiuthiiig  plane. 

A  Jolntliig'  plane  is  an  ex 
plane,  cliielly  used  when 

Ijoarda  whit'h  have  lc>  Vie : 


■  the  rough  usage  to  which  wiioden 
Fig.   1!M  i: 


The 


plane  (l-'iy 


traiong  trying 
great  iicturacy 
,g  tlie  ed^es  of 

.L;^■t)l 


liolluw  aarfacss,  mid  thcictni 


I  for  working; 
.  in  the  direction  (A  \\ji\ssa.\ 


""■ 


118       A   MANUAL  OF  CARPENTRY   AND  JOINKKY. 

a  convex  sole.  Fig.  196  shows  an  iron  adjustable  eircukr  plane 
which  in  !La  iiiiprovemEnC  upon  the  wooden  conipasti  plnne,  aa  it 
ran  be  ndjiiated  readily  to 
ariy  required  curve. 

The  rebate  plane  (Fig. 
107)  ban  a  cutter  equal 
in  width  to  the  width  of 
the  plane.  The  cutter  is 
placed  at  an  oblique  angle 
with  the  edge  of  the  sole 
of  the  plane,  the  cutting 
edge  being  straight.  Ita 
ik  Hurfacea  such  an  rebate*. 


:b  confined  to  the  planing  of  s 


The  length  of  this  plane  is  ubout  9"  and  its  width  varii 

A  plou^  (Fig.  198)  is  a  plnne  used  for  making  grot 
the  diiection  of  the  grain  of  the  wotrti.     This  is  a  somewhat 


complicated  tool  and  consists  of  a  stock  which  holds  I 
cutter,  and  a  movable  fence  which  is  secured  lo  the  stock  by 
means  of  two  arms.  These  arras  are  either  screwed  or  hdd 
with  wedges.  Tlie  cutter,  which  varies  in  si^e  Hccordiog  to 
the  size  of  the  groove  required,  is  held  in  position  by  met 
of  a  wedge.  A  second  iron  fence,  used  to  govern  the  depth 
of  groove  required,  works  with  an  adjustable  screw  against 
the  stock. 

The  bnUnaEa  plane  (Fig.  199)  is  a  small  [ilane  having  the  cutler 
as  near  the  fi-ont  end  of  the  sole  as  poHsiliie. 

Other   planes   such  as  the  mali-JHUster  {Fig.   200),    ehariut 
(Fig.  SOU  '■wider  (Fig.  302).  hmul  (Fig,  203),  ovolo.  tAmguiwg.  a 


ctrrmro  tools. 


ij  uml  ulniiist  tnuumeralilc  muulding  planen,  are  used  for 
Bfial  pilipi>wea  m  IihiuI  work. 


The  spokesbaTe  (Fig.  ^04)  is  a  special  kind  oi  ataaXX  hand  plane 
nued  for  finishing  curved  surfaces. 
SliajpenliiK.     Tlie  ciittiug  edge  of  the  plane-iron  or  chis«l  is 


obtained  by  first  erlndlng,  and  afterwards  rubbing  upon  an 
Dil-Btone.  The  oil-stone  is  of  even  texture,  ahould  not  be  too 
hard,  and  a»  its  name  implies  is  kept  lubricated  with  oil. 
md  "Arkanaas"  are  among  the  diSetent  tosAa  ^ 


120      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

oil-stones  in  general  use.  Tlie  grinding  angle  of  the  cutter  is 
from  20°  to  25° ;  the  sharpening  angle  varies  from  25"  to  40°, 
becoming  slightly  greater  each  time  the  tool  is  sharpened. 

Small  oil-stones  called  "slips"  are  used  for  sharpening  the 
concave  (hollow)  cutting  edges  that  are  found  in  bead  and  hand 
moulding  plane  cutters,  the  spokeshave,  and  other  tools  with 
curved  cutting  edges. 

Chisels. — These  may  be  divided  into  firmei\  paring  and 
mortising  chisels^  and  gouges.     Chisels  are  made  in  all  sizes  from 


JL        l\ 

^\ 

/'v 

« 

1 

1 

Fm.  205.—  Types  of  Firmer  Chisels. 


Fk;.  20C.— Paring  Cliisel. 


one-sixteenth  of  an  inch  to  2  inches  in  width.  They  consist  of  a 
steel  blade  with  the  cutting  edge  at  one  end,  and  a  "  tang,"  on 
to  which  the  wooden  handle  is  fitted,  at  the  other  end.  The 
firmer  and  paring  chisels  are  similar  in  shape  (Figs.  205  and  206), 
the  only  dilference  being  that  the  firmer  chisels  are  a  little 
stronger  than  the  paring  chisels  to  withstand  rough  usage  and 
the  occasional  use  of  the  mallet. 

Paring  chisels  often  have  bevel  edges  as  shown  in  Fig.  206. 

Mortise  chisels  (Fig.  207)  are  much  stronger  than  firmer  chisels, 
as  they  are  subjected  to  more  rough  usage  in  the  making  of 
mortises. 

Ck>iig-es  (Fig.  208),  are  chisels  with  curved  cutting  edges  ;  the 


CUTTING  TOOLS. 


121 


cutting  edge  may  be  ground  on  the  hollow  or  on  the  rounded 
surface.  The  grinding  angle  as  well  as  the  sharpening  angle  of 
chisels  are  the  same  as  in  the  plane  irons  (p.  116). 


Flo.  207. -Mortise  Cliisel.  Fia.  208.— Gouge.  Fia.  209.— Socketed  Chisel. 


The  slip  is  used  for  sharpening  gouges. 

Socketed  diisels  (Fig.  209)  instead  of  having  a  tang,  are  pro- 
vided with  a  socket,  into  which  the  handle  fits,  at  the  upper 
end. 

The  bandies  are  of  hard  wood  :  box,  beech,  and  ash  being 
^sed.  A  brass  ferrule  is  usually  put  on  the  lower  end  of  the 
chisel  handle  to  prevent  it  from  splitting.  Handles  of  chisels 
that  have  to  be  used  for  very  heavy  work  with  the  mallet  are 
often  hooped  at  both  ends. 

Other  cutting  tools,  such  as  the  axe^  adze — used  chiefly  by 
ship-builders — and  the  draw-hiife  (a  tool  used  by  coach- 
builders),  need  no  detailed  description. 


122      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


BOBING  TOOLS. 

Brad-awl  and  Gimlet. — The  brad-awl  and  gimlet  are  U 
of  the  simplest  kinds  of  boring  tools.  The  method  of  their  ii 
also  illustrates  the  principle  of  most  boring  bits.     The  bracl-a 

(Fig;  210)  has  a  wedj 
shaped  cutter,  and  requii 
the  exertion  ot  pressi 
during  its  use.  Care  m- 
be  exercised  to  have  1 
cutting  edge  .across  1 
fibres,  or  it  will  be  lia 
to  split  the  wood.  T 
gimlet  (Fig.  211)  has 
screw  feed,  and  therefc 
instead  of  a  pressure 
rotary  movement 
necessary. 
Brace  and  Brace-bits. — Boring  is,  however,  generally  i 
formed  by  the  brace,  and  brace-bits.  By  means  of  the  \m 
the  principle  of  the  lever  is  applied  to  exert  an  increased  fc 


Fig.  210.— Brad-awL 


Pig.  211.— Gimlet. 


Pig.  212.— Brace. 


Fio.  213.— Shell 
Bit. 


Fio.  214.— Nose 
Bit. 


Fio.  215.— S 
Bit. 


whereby  the  brace  bit  is  easily  forced  into  the  wood.  Mi 
different  types  of  brace  are  in  use  ;  perhaps  one  of  the  besi 
the  ratchet  brace  (Fig.  212)  in  which  the  turning  movem 


BORING  TOOLS. 


123 


tnay  be  effected  by  a,  rack.  Tiii«  brace  enables  bnring  to  be 
dune  in  cdi'nerB,  and  other  awkward  positinns  where  the 
iirdinary  circular  nioveinent  of  a  bmce  could  Tiot  be  applied. 

*nie  Bhell  (Fig.  213)  and  noss  bila  (Fig.  214)  are  very  Bimilar  ; 
ill  the  latter,  a  projecting  nnse  aEsiets  in  clearing  the  hole. 
ITiH  nose-bit  is  specially  Biiitable  for  boring  holes  2"  to  3"  deep 
in  the  direction  of  the  grain  of  the  wood.  The  STrisB-Hit 
(Fig,  B15)  hajB  a  spiral  point.  These  three  bits  are  chiefly  used  for 
boriDR  for  nails  nnd  screws  ;  their  diainctcrs  are  from  ,'j"  to  J". 


Fio.  aT.-Aumror 
twisted  BFt, 

The(i«iitroliIt(Fig.  216)  has  three  separate  cutting  pai-ta.  Tte 
wing  diameter  variea  from  J"  to  1^".  It  is  a  clean-cutting 
M,  but  [■equires  presanre  during  the  operation,  and  if  the  holes 
to  Iw  bored  are  nioi'e  than  2"  deep  it  is  liable  to  become  choked 
nnleM  the  accumulating  chips  are  frequently  removed. 

The  anger  bit  (Fig.  217)  exists  in  many  forms.  Its  helical 
'liapB  renders  it  suitable  for  most  woik,  except  in  very  hard 
wftods.  Tts  central  guide  point  has  a  spiral  screw  feed  ;  this 
ii'ii'lers  Ijoring  acrosH  the  grain  possible  with  veiy  little  presanre. 
Allien  Iioi'ing  with  an  auger  bit  in  the  direction  of  the  giain  of 
Mbk  JB  reqairad,  as  the  screw  feed  ti.\oafc  wjMfc 


124      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

strong  enough  to  draw  the  bit  into  the  wood.     The  **  Forstn 
bit  (Fig.  218)  is  useful  for  flat  bottom  or  angular  boring. 
Expanding  brace  bits  (Fig.  219)  are  also  to  be  obtained.   Tl 


«*■ 


.  1 

..V 


V-^-*«a4 


Fio.  218.— Forstuer  Bit. 


Fio.  219. — Expansion 
Brace-bit. 


Fig.  220.— Auger 


are  capable  of  adjustment  within  certain  dimensions,  and  p 
very  useful  tools. 

Other  brace  bits,  such  as  the  screiv  driver  bit,  countersin 
(for  iron  and  wood),  rirners,  etc.,  are  also  used.  For  h 
work,  aiiger  bits  with  long  stems  are  used  (Fig.  220)  ;  the^ 
provided  with  wooden  handles  for  turning  purposes. 


VICES  AND  CRAMPS. 

Bench  Vice. — The  woodworker's  bench  is  usually  pro^ 
with  a  vice  for  holding  the  material  being  worked.  This  vi 
fixed  against  the  side  of  the  bench  at  the  left  hand  end.  ]\ 
different  kinds  of  vice  are  in  general  use,  some  of  these  I 


VICEH   AND  CRAMPS.  ' 

Iff  antiquated  and  primitive  chai'actei'.     Others,  of  more  recent 

I   iawDtion,  Hre  valuable  tinie-savinj;  appliances.     The   wooden 

which  18  about  3"  i 


laiawetar,  ia  one  of  tlio  old 
B-fype.  A  steel  threaded  screw 
K.IB  Hnnietinies  used,  instead  of 
[  the  wooden  screw.  In  either 
J  is  through 
the  wooden  jaw  of  the  rice. 
Wsny  patent  vices  are 
"*"  the  market.  Some  of  I 
these  are  called  "  instan- 
'^aeona.grip,"  because  they 
^t*  fitted  with  a  ratchet  that 
''"owb  the  jaw  of  the  vice  to 
"^  drawn  out  ;  when  the  spring  is 
''ctioii.  It  is  reasonable  to  exjiect  that  a  good  bench-vice  will  in 
*•  sbort  space  of  time  repay  its  cost  as  compared  with  tliat  of  the 
»v^fa-__^  old-fashioned  wooden  scrow-vices  that  are  still  in 
^^^^      use  in  some  workshops. 

\^M  Cramps. — Cramps,  as  the  name  implies,  are  usefl 

9  for  holding  together  framing,  such  as  Hashes,  doors, 

m 


s  released  the  screw  ci 


*la  ;  for  cramping  floor  l>oards  ;  for  holding  down  work  on  the 
banc!)  ;  and  for  many  other  purposes.  Figs.  222  and  223  sliow 
Lwn  kinds  rif  nosh  cramp.     Each  consists  of  a  Btee\  tev  "OJivV.  wv 


126      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


adjustable  shoe  at  one  end,  and  a  jaw  attached  to  a  scre^ 
threaded  shaft  for  tightening  up  as  required.  Sash  cramps*  a  *"^ 
made  in  a  large  variety  of  sizes  and  strengths  to  suit  th©  i  r 
diflferent  applications  in  the  fixing  together  of  structur^^'- 
Figs.    221    and   224  show    two   types  of  floor  cramp,     Tb  i^ 


Fig.  225.— G-Cramp. 


Fio.  226.— Bench  Holdfast 


appliance  is  so  constructed  that  it  will  clip  on  the  edge  of  th^^ 
floor  joist,  and  force  the  boards  into  position.     Other  cramps^-^ 
such  as  the  0-cramp  (Fig.  225)  and  the  bench  holdfast  (Fig.  226]^^ 
are  too  well  known  to  require  description. 


SUMMARY. 

Tools  should  not  only  be  of  the  best  materials,  but  should  be  kept 
constantly  in  good  order. 

The  commonest  measuring  tools  are  the  r?t/e,  ta/pe  or  chain 
measure^  and  yradiuUed  rods.  For  testing  the  straightness  and 
accuracy  of  work,  the  straight  edtje^  try  nqiuirey  hiding  hevd^  gauges^ 
compasseSf  spirit -level,  plumb  nde,  chalked  line,  etc.,  are  used. 

Among  cutting  tools  are  the  various  types  of  sav:sj  planes,  and 
chisels.  Saws  require  the  teeth  to  be  "set"  to  obtain  clearance  in 
cutting.  They  are  sharpened  with  a  triangular  file.  Planes  and 
chisels  are  first  ground  to  an  angle  of  20"*  to  25**,  and  afterwards 
repeatedly  sharpened  upon  the  oil-stone,  the  cutting  angle  varying 
from  25^  to  40^ 

Boring  tools  include  the  hrad-atol,  gimlet,  brace  and  hra^e  hits,  and 
aiujer.     There  are  many  types  of  brace  bit. 

For  holding  in  position  the  material  which  is  being  worked,  and 
as  an  aid  in  putting  together  framed  structures,  vices  and  cramps 
aro  indispensable. 


QUESTIONS  ON  CHAPTER  V.  127 


Questions  on  Chapter  V. 

.  1  -     Make  sketches  of  a  try-square,  a  sliding  bevel,  and  a  mortise 
gauge.    State  for  what  each  of  these  tools  is  used. 

2.  Give  a  description  of  the  teeth  of  a  rip  saw,  and  of  a  dovetail 
saAv,  and  state  the  reason  for  their  shapes.  Make  a  sketch  of  a 
ploiigh,  and  state  the  purposes  for  which  it  may  be  used.  (C.  and 
G.  Ord.,  1900.) 

3.  What  is  meant  by  the  set  on  a  saw  ?  What  will  be  the  eflFect 
of  ^:ising  a  saw  without  set?  Show  by  sketches  the  amount  of  sot 
re^liiired  for  (a)  a  hand  cross-cut  saw  when  cutting  rough  unseasoned 
timljer ;  (6)  a  rip  saw  for  cutting  dry  stuff. 

'4-.  Make  sketches,  and  describe  the  following  tools  and  their 
U8«5s  :  tenon  saw,  spokeshave,  and  smoothing  plane.  (C.  and  G. 
Prel.,  1900.) 

S.  (o)  Make  a  sketch  of  a  jack  plane.  What  is  the  object  of  the 
ca-X*  or  back  iron  ?  (b)  Describe  the  sharpening  of  a  centre  bit,  and 
it»   outting  action.     (C.  and  G.  Pre!.,  1899.) 

^-  Make  sketches  and  describe  the  uses  of  the  following  tools  : 

(1)  Trying  plane. 

(2)  Smoothing  plane. 

(3)  Beads. 

State  why  (2)  is  sometimes  fitted  with  an  iron  face,  and  how  (3)  are 
^s^Hi  and  sharpened.     (C.  and  G.  Prel,  1902.)    ^ 

7.  Show  by  sketches  the  cutting  edge  of  (a)  a^^a^k  plane  iron, 
\y)  a  smoothing  plane  iron,  (c)  a  firmer  chisel.  State  approximately 
tile  grinding  and  the  sharpening  angle. 

8.  Describe  fully  with  sketclies  the  cutting  edges  of  the  following 
^Is,  and  explain  the  proper  method  of  sharpening  each  :  firmer 
^^isel,  mortising  chisel,   gouge,   one   kind  of   carA^ing  tool,  trying 

•  plane,  rebate  plane,  rip  saw,  spokeshave.     (C.  and  G.  Ord.,  1895.) 

9.  State  for  what  purposes  the  following  tools  are  used :  firmer 
chisel,  back  saw,  jack  plane,  router,  side  fillister,  chariot  plane. 
(C.andG.  Ord.,  1897.) 

10.  State  for  what  purposes  the  following  tools  are  used  :  chisel, 
tenon  or  back  saw,  gouge,  jack  plane,  smoothing  plane,  trying 
plane,  rebate  plane,  old  woman's  tooth,  plough,  sash  fillister, 
trammel.     (C.  and  G.  Ord.,  1893.) 

11.  Describe  the  following  tools  and  their  uses.     Give  sketclies  : 

(1)  Brace  and  different  forms  of  bits.  \. 

(2)  Bow  saw. 

(3)  Firmer  chisels  and  gouges.     (C.  and  G.  Pre!.,  l^Y."^ 


128       A  MANUAL  OF  CARPENTRY   AND  .TOINKRY. 

12.  Describe  the  form  and  use  of  ten  ordinary  kinds  of  bit  for 
with  a  hand  brace.     (C.  and  G.  Ord.,  1896.) 

13.  Give  a  short  description  of  six  ordinary  tools  used  by 
carpenter  and  joiner.     (C.  and  G.  Prel.,  1897.) 

14.  State  the  difference  between  a  sash  cramp  and  a  floor  crai 
Make  a  sketch  of  each  kind. 

15.  Describe   the  tools  in   your  possession,  their   uses,  and 
special  advantages  of  any  not  in  every-day  use.     (C.  and  G.  H< 
1895.) 


CHAPTER  VI. 
WOODWORKING  MACHINEBT. 

Q'eneral. — The   use  of  woodworking  machinery  is  now  so 
extensive  and  so  general  that  many  of  the  hand  tools  required 
"y  the  craftsman  of  thirty  years  ago  have  become  obsolete,  and 
*^^    unknown  to  many   Workmen  of  the   present  day.     The 
demand  for  labour-saving  appliances  has  led  to  the  making  of 
inachines  which  are  capable  of  peiforming  almost  every  opera- 
tion necessary  in  woodworking.     Sawing  by  reciprocal  frame, 
"y  circular  and  by  band  saws  ;  planing— either  one,  two,  or  all 
four  sides  at  the  same  time ;   moulding  in  almost  every  con- 
ceivable design,  in  either  straight  or  curved  work  ;  mortising, 
^^ioning,  dovetailing,  trenching,  even  sandpapering,  as  well  as 
"cx  nailing,  are  all  operations  capable  of  being  performed  with 
Machinery  at  the  present  time.    Indeed,  machines  called  "general 
joiners  "  are  to  be  obtained  which  are  capable  of  several  different 
operations. 

The  very  great  variety  of  woodworking  machinery  prevents 
^ere  than  a  casual  reference  to  some  of  the  most  important 
types. 

SAWING. 

Vertical  Log  Frame. — The  vertical  log  frame  saw  is  a  very 
heavy  machine,  capable  of  sawing  logs  up  to  50"  in  diameter. 
It  has  a  movable  carriage  which  carries  the  material  to  be 
sawn,  and  is  provided  with  a  feed  motion.  This  carriage 
works  through  a  strong  iron  frame  into  which  the  saws  are 
fixed.  The  saws  work  with  a  reciprocal — up  and  down — motion. 
Mftny  of  these  machines  are  capable  of  holding  as  maii^  ^ja  icsv^*-^ 

M.C.J.  I 


ai_. 


MO      aVaSUAL  of  carpentry  ASD  JOINEEY. 

BawB  at  (iDce,  and  thus  of  converting  the  log  into  thh  numberof  fl 
Lioanls  at  one  feed.     Of  couiTie,  n.  frame  with  n  large  nnmbec 
of  Baws  I'equireB  a  eonaideralile  amount  nt  driving  power,  n  ~ 
entails  a  slow  feed ;   utill,  tiieas  are  compenaatetl  for  hj  th^ 
HdvADtnge  of  converting  a  lai'ge  log  at  one  opsratioii.      F 


SAWINO, 


18! 


bila  nnfi  |ilaiikn  into  thinnef  bciai-ds,  Tlie  use  of  this  machine 
"  lAonHidei-ral  more  eeonomiual  than  thab  of  the  circular  saw,  !ioth 
E  rei;srds  prodiictioti  and  economy  of  niHt«rial  wbeti  the  timber 
'  I'einj;;  cut  into  several  boards  ;  for,  in  the  fiist  pliice,  a  nuruber 


nf  BtwB  wort  together,  iiiid,  8ocondly,,the  aaws,  being  in  tennion, 
WK  thinner  thitn  the  average  circular  saw,  and  thna  eiititil  leiu 
t«  of  wood.  Mauy  different  types  of  this  machine  enst,  and 
v.  £29  -.mA  S30  are  good  examples.  The  main  featbre  is  that 
tatmtig  fi-niue  cai-ries  n  number  of  vertical  sawn  which  have  a 
neiprocal  motion,  fig.  229  illuatratea  a  doiihle  deal  frame— 
D  iMhieh  two  deals  can  be  aawn  a.b  tibe  sanw  tuaft. 


132      A  MANUAL  0?"  CARPENTRY  AND  JOINERY. 

Fig.  230  ahowB  a.  tiiiglB  deal  frame,  a  machine  which  only  aJl( 
of  one  deal  being  ]Ji««ed  thi'ough  the  niiiehineatoncB.  Thai 
of  these  machines — that  is,  the  means  adapted  for  drawing  i 


see.— Uoubla  Deal  Frajui  BaW. 


material  into  the  machine — ia  obtained  by  geared  rollers  W 
grip  the  inat«riail  to  be  sawn  and  draw  it  into  the  machine. 
Horizontal  Log  Fiame.— The  horizontal  log  frame  cob 
of  a  frame  holding  a  reciprocating  saw  which  works  to  and 
in  a  horizontal  direction.  Occasionally  twn  liaws  are  usei 
the  same  time.  This  uiachine  is  also  provided  with  a  mo* 
carriage,  upon  which  the  log  to  be  cut  la  placed.     This  carr 


SAWING. 


133 


*  fitted  with  a  feed  motion  capable  of  being  regulated  to  suit 
tile  travelling  speed  of  the  uiaterinl  towards  the  eaw.  Figs.  231 
HDdaSg  illustrate  this  class  of  machine.  In  Fig.  232  two  saws  are 
shown  in  position.  An  advantage  claimed  for  this  machine  over 
tie  vertical  type  ia  that  it  always  allows  of  the  lug  being 
sxumiued  during  the  cutting,  and  therefore  of  regulating  the 


Singli 


tickness  of  each  board  according  to  the  qujditj  of  the  timber 
it  is  well  known  that  defects  which  would  not  impair  the  vatue 
of  planks  three  inches  thick  might  prove  detrimental  in  boards 
nniier  one  inch  in  thickness,  especially  when  sawing  up  choice 
birdwood  logs  for  panels,  furniture,  etc. 

ClOSB-CUt  Saw. — A  reciprocating  cross-cut  saw  used  for  cross- 
tutting  large  logs  and  balkn  of  timber  is  illustrated  in  Fig,  233. 
b  special];  adapted  lor  use  in  tbe  timber  yard,  ot  eng^i 


woi'ks,   where 
reciprocal  ill. 


illuBtiutea  a.  bund  saw  and  frame,  fitted  with   a  geai'ed  roller 
feed  ;  it  ia  used  for  sawing  deals  into  buai'ds. 

Lighter  band  saws  are  very  lurgely  used  fur  cutting  curved 
work  of  almost  every  conceivable  design  ;  tbe  saws  vary  consider- 
ably in  width  and  may  be  aa  narrow  aa  oue-eighth  of  an  iiiub. 
Sucli  baud  saws  have  heavy  cast-iron  fi-aiuea  to  carry  tba 
pulleys  around  which  the  saw  runs.  Figs.  236  aod  237  show 
two  types,  one  of  which  is  provided  with  a  motor  for  di'iviog 


19S      A  MANUAL  OP  GARPSNTRT  AN»  JOISKRV. 

purposes.  The  feeding  of  the  material  in  these  aaws  is 
liy  hand,  and  in  most  lywes  tlie  Ulile,  which  in  from  3  to  4 
square,  is  onpable  of  being  tilted. 


Oircnlar  Sawa. ^Circular  aawa  are  more  extenaively  used 
than  any  others  for  the  mass  of  ordinary  Hawing.  The  general 
arrangement  is  to  have  a  heavy  taet  iron  frame,  the  top  (tahie) 
of  which  in  smooth  and  perfectly  plane,  and  a  ahort  Rhaft  (an 


illustrated  separately  in  "Fig.  23B)  which  runs  in  l>earinga  under- 
neath the  table.  The  circular  saw  is  fixed  upon  this  shaft  and 
runs  in  a  slot  in  the  table.  In  most  cases  either  the  shaft 
carrying  the  saw,  or  the  top  of  the  table,  is  construeted  no  that 
it  can  be  adjiisted^raiaed  and  lowered.  This  allows  of  accurate 
g  for  any  depth  of  saw  cut  that  may  be  required,  and  ia  of 


SAWISU. 


139 


tho  greatest  iLi|jortiiiit«  for  guneml  work.  The  size  of  the 
frame  is  proportionate  to  the  size  of  the  saw  used  and  the 
chamt-tor  of  the  work  to  be  executed.  Cii'L'ular  buwb  vary  in 
uize  from  T  feet  to  n  few  iochea  in  diameter.  With  the  larger 
sawB  tlie  finiiieu  require  to  be  very  iieavy. 

As  Ihe  amount  of  power  [■equired  for  driviriij  a  circular  saw  is 
coDHidenible  and  increases  with  au  intreiise  iu  tlie  size  of  the 
saw,  it  is  always  advisable  to  use  the  smallest  size  of  saw  that 
is  callable  iit  perform iii);  the  work  reipiired. 


The  speed  at   whidi   saws  are  driven  varies   with   the   size 

of  the  saw  ;  the  cu-cunifereiitial  velocity  should  not  be  leas  than 

OOOO  f Bet  per  minute.     Por  example,  a  circular  saw  of  12  inches 

'n  iliainetei'  kIiduUI  make  about  30<K)  revolutions  per  minute. 

On  the  top  of  the  table  is  arranged  a  movable  fente  against 

Alidh  the  timber  slides  when  the  machine  is  being  used  for 

sawing.    The  fiu-e  of  tliia  fenoe,  which  is  from  two  to 

e  feet  long,  is  parallel  to  the  blade  of  the  saw,  and  the  fence 

^adjustable,  generally   by  means  of  a  sci'ew  and  hand  wheel. 

~s  is  aliowii  in   Fig.  239,  which  illusti-ntes  a  tyjie  of  cin^ular 

W  bttatAi  iu  ifeijurul  i;se.     The  fence  is  arranged  gene.vjOiX'j  «i 


I 


1*0       A  MANUAL  OF  CAKPENTRY  AND  JOINERY. 

tliat  it  can  lie  tilted  for  sawing  the  edges  of  timber  at  other 
than  right  aaglea.  In  the  heiivier  machiiiea  the  fenoe  as  well 
as  the  top  of  the  table  ai'e  often  piovided   with   rollers  pro- 


jecting alightly  beyond  the  surface  to  lessen  the  friction.  The 
fence  is  often  provided  with  an  appliance  in  the  shape  of  a 
lever  and  weights,  whereby  the  material  is  held  against  the 
fence  during  the  sawing,  as  shown  in  Fig.  240. 


(1  of  heavy  material  with  circular  aawa,  some 
inechtiuical  feeding  anangement  is  necessary.  Several  different 
devices  are  in  ante  ;  among  these  is  a  iiidial  arm  carrying  flut«d 
rollers  which  are  driven  with  chain  gear  (Fig.  240) ;  a  rope  or 
chain  drag  as  shown  in  Fig.  :241,  which  also  shows  loose 
carriages  £or  supporting  the  ends  of  long  timbei-s;  while  ia. 


SAWING. 


141 


some  of  the  heavier  machines  the  table  is  of  considerable 
length  and  runs  upon  rollers  as  illustrated  in  Fig.  242. 

Saw  Teeth. — In  both  frame  and  circular  saws,  the  saws 
used  vary  in  thickness  according  to  their  size  and  the  nature  of 
the  material  being  operated  upon.  As  the  frame  saws  are  held 
in  tension  they  are  usually  thinner  than  the  larger  circular 
saws. 

The  size  and  shape  of  the  teeth  of  saws  used  in  machine 
"work  are  also  regulated  by  the  kinc^  of  material  to  be  cut  and 


Fig.  243. 


FiQ.  244. 


,\AAAAA/VVVW 


Fio.  245. 
Types  of  Saw  Teeth. 


the  manner  in  which  it  has  to  be  cut.  The  larger  the  teeth,  the 
rougher  are  the  cut  surfaces,  especially  if  any  attempt  is  made 
to  force  the  work  through  the  machine.  Fig.  243  shows 
a  typical  shape  of  tooth  used  for  cutting  soft  wood  such  as 
pine  and  deal.  For  hard  wood  such  as  oak,  birch,  walnut, 
etc.,  a  tooth  with  less  hook,  as  shown  in  Fig.  244,  is  more 
suitable ;  while  for  cross-cutting,  the  shape  of  the  tooth 
more  nearly  approaches  that  of  the  hand  saw  (Fig.  245). 
Many  variations  from  these  shapes  are  in  common  use,  and 
are  the  subject  of  considerable  differences  of  opinion  among 
experts. 

As  explained  in  the  remarks  upon  hand  saws  (Chap.  Y.), 
the  teeth  of  saws  require  to  be  "set"  in  order  \iO  ^wfe  XJtifc 


'  Iffi      A  MANUAI.  OF  CARPENTRY  AITO  JOINRRT. 

ne  either  with  the 
There  are  one 

o  types  of  circular  saw  however,  that  do  not  require  setting. 
e  Evage  saw  ia  a.  type  of  circular  saw  which  is  used  for  sawing 
-y  thiTi  boanls.  TJiia  bhw  ia  inufli  thit-Ver  ftt  the  ceiitrti  than 
tlie  circuiiiferentp,  anil  Iihh  one  Saoe  uf  llie  aaw  perfectly  true. 


'    ric  i:40.— Ty[w  of  Snw  Sliarpcnlns  Kuhliio, 


The  result  is  that  the  saw-cut  is  yaiy  thin,  und  conaequently 
tha  waBt«  of  material  is  very  little,  and  the  clearance  is 
effected  by  the  giving  way  of  the  thin  liourd  which  is  cut  off. 
Such  a  saw  does  not  require  any  set ;  it  canntit  Iw  used  for 
cutting  thick  pieces  of  timber. 

Another  type  of  circular  saw  that  does  not  require  setting  is 
the  hallow-grounil  saw,  u  saw  which  is  chiefly  used  for  cmsa- 
ciitting  purpo^ies  and  for  other  special  work.  This  saw  is 
thicker  at  the  cit'cuniference  than  at  the  oentre. 


SAWINfi. 


M3 


The  teetli  uf  frame  and  circular  sawa  i»v  HliiirpenKtl  uitber 
with  the  file  or  with  the  emery  ■whuel.  When  sharpened  with 
the  file,  the  teeth  require  periodic=iUy  guUetitig  (re-cutting  to 
the  proper  shape),  aa  tlio  piiint  only  of  the  tooth  is  filed  during 
sharpening.  WLen  the  emeiy  wheel  is  used,  the  sine  of  the 
^L       teeth  ia  kept  constant,  ami  no  guUeting  is  necessary.     Figs.  246 


to  248  show  three  diffeieut  types  of  emery  wheel  usi;d  for 
ahai'peuing.  The  emery  wheel  is  also  used  fur  sharpening 
L-utters  of  planing  and  moulding  machines. 

Large  circular  aawa  inquiia  uiinsiderable  akiU  in  their  n 
pulation  in  order  to  oLtain  the  best  results  The  "  packing"  of 
a  drcular  saw  in  the  slot  in  which  it  wui'ks  is  a  necessary  opera- 
bian,and  requires  great  care  and  )udgiiieiit.  Tliu  packing  consists 
pea  cord  folded  at'ound  a  place  of  •wood,  wA  vaiah^ 


Planing  niftchinea  nre  used  to  cdnvert  the  sawn  material  into 
R  required,  and  to  niake  the  surfaces  smootU  and 
true.  To  attain  this  reHiilt,  nteel  cutters  are  mounted  id  strong 
cast  iron  frames,  either  as  stationary  cutters,  or  so  that  they 
revolve  at  a  very  rapid  rate.  The  revolving  cutters  are  1^ 
inted  upon  si^uare  or  specially  shaped  steel  hlocke,  which  ftre 
either  part  of  the  shaft  itself  or  are  fitted  ftcciirately  upon  ih» 
shaft.  The  cutters  must  be  secitred  firmly  with  bolts,  and 
arranged  so  that  they  accurately  balance  each  other,  as  they 
revolve  at  a  very  rapid  rate,  a.ad  exert  a  considenkble  centrifugal 
Scone.    It  is  very  easratial  tiM  tbo  bearings  of  such  machines 


PLANIN*;   MACHINES. 


14S 


be   of   the   best   material,  and   that   tliey  be    kept   lubricated 

'  Surface  Planer. — The  aimpleBt  kind  of  planing  machine 
(Fig.  249)  is  one  that  has  ciittars  bolted  upon  a  revolving 
spindle,  and  projecting  alightly  above  the  top  surface  of  the 
ta.ble.  The  speed  nf  tliiw  shaft  is  from  3000  to  4000  revolutions 
per  minute,  and  the  material  in  slid  along  the  top  of  the  table 
until  it  is  brought  in  contact  with  the  cuttera.  Such  a  machine 
ia  called  a  anrfkoo  planar  ;  it  haa  two  cutttii'n  varying  fi'oni  13  to 
IS  inches  long,  which  balance  each  other,  and  are  secured  with 


bolts  to  the  shaft.  In  some  machines  these  cutters  are  straight,' 
and  work  at  right  angles  to  the  edge  of  the  table  ;  in  others  the 
cutters  are  so  arranged  on  the  hloek  that  they  have  a  helical 
cutting  action.  In  Fig.  249  the  top  of  the  table  is  adjustable 
by  means  of  the  incliiied  slides,  and  is  regulated  with  the  hand 
screws  to  govern  the  thickness  of  the  shaving  to  be  taken  off. 
In  some  machiues  the  shaft  carrying  the  cutters  is  adjustable 
for  the  Rame  purpose.  A  movable  fence  which  can,  if  necessary, 
be  tilted  at  other  than  a  right  angle,  ia  arranged  on  the  top  of 
the  table,  and  by  its  aid  surfaces  either  at  right  angles  to  «ach 
other,  or  at  any  other  angle  (greater  than  a  right  angle),  can  be 
readily  planed.  Although  this  machine  is  perhaps  the  moat 
effective  for   aiirface  planing,  and   ia  useful  for   te\ia,tu\j  nr' 


146      A  MATTOAL  Ot  CARPENTRY  AND  JOINERY. 


cbatii feeing,  it  is  licit  economiL'nl  when  used  fnr  large  qiiantiti 
of  iiiiitei'iitl  rotjiiii'iiig  ta  be  Itnialied  of  exnutly  the  same  si: 
Tbe  feeding  of  aucli  a  mHcliine  is  generally  done  hj  hand. 

Panel  Planer.— A  heavier  machine  unnied  a  panel  planer  l 
revolving  euttera  enpabla  of  taking  a  width  iif  30",  and  working 
ill  A  heavy  cast  iixin  fi'ame.  Tliia  machine  lias  a  Dieclianiuil 
feed  ai-i-nngement  in  the  Bhape  of  flut«d  ixjllera  which  are  fiied 
almost  directly  above  the  cutteifl,  and  are  geared  to  regulate 
the  -speed  iif  the  feed. 

Tliicknessiiig  Machines. — Fig.  250  showa  a  machine  having 
superposed   tallies,   one  of   wiiLoh   is   plated  beluw   the  cuttep 


block  and  one  above  it.  The  former  ia  used  for  carrying  the 
timber  to  be  planed  to  a  definite  thickness,  and  can  be  raised  or 
lowered  to  suit  the  thickness  required.  Tlie  timber  ia  fe^ 
under  the  cutter  block  by  means  of  feed  rollers  placed  h 
and  behind  the  cutter  block.  The  upper  table  ia  usei 
surface  planing,  and  ie  fed  by  Land.  It  is  cafialile  of  taki 
material  up  to  24"  in  width  and  6"  in  thickness. 

Figs.  251  and  S5S  show  two  tyjiea  of  a  heavier  and  more  eoi 
plicat«d  machine,  which  is  capable  of  planing  all  four  aidea 
the  same  piece  at  one  operation,  'llie  cuttern  that  plane  ti 
edgen  are  mounted  on  vertical  spindles.  Such  machines  a 
provided  with  gear-driven  fluted  rollers,  which  draw  thW 
material  into  the  machine  and  foi-ee  it  though.  This  claaa  of 
}  wil]   take  in  material   up  to  34"  by  g*.  and  ia  x 


PLANING   MACHINES. 


Fio.  2S3.— PUil 


148       A  MANUAL  OF  CARPENTRY  AND  JOINERY, 


ml  nsatch  boards  with  aiti  ] 
I'ebatad.  edges  ;   and  akict)   | 


extenBively  for  preparing  floci 
square,  grooved  and  tongued, 
boards,  etc 

Many  of  these  machines  have  stationary  cuttera  fined  m 
macliiiie ;    theae   jiroduce   a   better   finished   surface   thag. 
revolving   cutters.     This  ia  especially  the  case  with 
constantlj  uaed  in  the  preparation  of  floor  and  match 
Such  machines  are  capable  of  pi'oducing  this  class  of 
the  rate  of  from  80  to  100  feet  per  minute. 

Moulding     Machines. — Moulding     machines     are 
machines  in  which  the  cutters  are  shaped  ao  that  the 


material  passing  through  them  is  of  ornamental  deaigt 
shape  and  design  of  the  moulding  produced  i»  only  liini 
the  impossibility  of  preparing  "  undercut "  mouldings  j 
means.  It  is  often  advisable,  in  order  to  save  material,* 
timber  used  for  mouldings  should  be  sawn  I 
rectangular  shape,  and,  also  for  economical  reasona,  i^j| 
desirable  to  build  up  large  mouldings  by  preparing  tJ 
or  more  separate  pieces.  Many  such  machines  (Fig..l 
made  with  the  top  cuttera  carried  upon  a  canttajfl^ 
This  allows  of  the  cutters  being  lixed  upon  the  blocka,^ 
they  do  not  have  an  unnecessary  leverage  or  projeotiol 
the  block. 
A  TorticaJ  splniUe  moulding  machine  conaUi 


ISO       A  MANUAL  CtV  OARPFNTRY  ANB  TODiKR?. 

table,  upriii  which  is  arrtknged  a.  vertical  sbaft  which  carries 
cutters.  With  such  uiachinea  the  material  i-equirea  to  be  pre-] 
vioiialy  planed  to  the  reqaired  size,  and  only  one  surface  a 
moulded  at  one  time.  An  advantage  i)f  tliie  daiis  of  machine  iaM 
that  curved  surfaces  of  almost  any  radii  can  be  treated  as  easily  ■ 
as  straight  ones.  Such  machines  are,  as  a  rule,  hand  fed,  and] 
Lave  a  reversible  luoliou  to  suit  the  frrain  of  the  wood.    Fig.  2531 


U  an  illuHtratiuii  of  this  class  of   machine.     Fig.  354  ahowa  a 
nini^hine  that  cau  be  used  foe  either  nmulding— stii^^t  i 
circular — housing,   trenching,  therming,  vecessing,  etc 
B[)Uciall,y  a)i]ilicalile  tn  stich  work  as  the  treiiclitng  of  the  string^ 
biMii'dii  of  Kt«irs,  the  pr«]Hiration  of  raised  panels,  of  rectaogt ' 
or  piilygunftl  shaped  staiv-lwilustGi-s,  and  other  similar  work. 

Tenoning  Machines.  -  As  moat  fimuing  in  held  together 
mortise  and  tenon  joints,  both  tenoning  and  mortising  nntchiii 
are  largely  nsed.    The  tenoning  machine  (Fig.  Sriri)  cooaiata  a 


B^fm 


MORTISING  MACHINES. 


^^Mi  fmnie  which  holds  two  sets  'if  ciittem  woi'kinp  opposite  eafh 
other,  and  c^apiible  of  adjuBtnient  to  suit  varying  thicknesses  of 
teiiona,  Tlie  cutters  are  mniinted  ou  binclia,  so  that  Ihey  have 
a.  helical-cutting  action.  Additional  small  cutters  are  altw  fixed 
upon  the  blocks  which  cut  thrcmgh  the  fibres  at  the  shoulders, 
I'he  table  upon  which  the  material  is  held  by  means  of  a  lever 
in  provided  with  a  lateral  motion,  and  is  fitted  with  guides. 


,  A  Mortising  Maclxine  ia  used  for  making  rectangular  holes 
"  lurtises)  in  framing.  Fig.  2.16  shows  a  type  of  hand  mortising 
t%tac)iine,  in  which  a  strong  chisel  in  given  a  reciprocal — up  and 
down— motion  by  means  of  the  lever.  The  table  ia  fitted  with  a 
hand  wheel  for  holding  the  material,  and  works  in  slides  which 
allow  both  a  longitudinal  and  a  lateral  movement.  Fig.  257 
nhowB  another  machine,  which  ia  fitted  with  boring  apjiaratus  in 
addition  to  the  incirtise  chiuel.  Fig.  258  shows  a  power  mortiaiug 
machine,  where  the  motion  of  the  chiabl  is  obtained  by  means 
of  S,  crank.     Boring  apptuulus  is  kIbo  lilted  to  Uuft  luac'C^i&ft. 


168      A  MASTTAL  OT  OARPENTRT  ASTO  JTOINBftT. 

Another  type  of  power  mortising  machine  is  shown  in  Fig, 
This  conaista  of  an  enillea-i  link  uhain  of  cutters  whiulj  has  a 
oontinuQUB  motion.    The  cutt«ra  are  hrought  down  to  the  wurk, 
which  is  fastened   upon  the  tahle,   by  means  of  a  foot  lever. 
Fig.  260  shows  a  horing  and  elot-moi'tiBiug  niacliine,  in  which    ' 
the  horing  bit  works  in  a  horizontal  position.     An  esamii 


of  the  illustration  wiil  show  the  various  movements  of  which 
this  machine  is  capable. 

Oombination  Machines. —A  class  of  machine  very  suitable 
for  small  workshopB  where  a  variety  of  work — but  not  aufficien 
in  quantity  to  wanunt  eeparale  machines  for  each  kind  of  work 
—is  executed,  is  known  aa  a  general  Joiner.  FigH.  S61  and  S62 
ahow  two  different  views  of  such  a  machine.  It  is  capable 
dimenuon  sawing  to  6"  deep,  BUiface  planing  lo  12"  wide,  thick- 
ueasing  "amall  Btuff,"  variety  moolding,  tenoning,  boring,  and 


164      A  MANUAL  OF  OARPBNTRT  ASD  ^TOISBRT. 

slot  luoi'tiaing.  The  circular  saw  taljle  is  held  in  slides  against 
tbe  stand,  and  is  provided  with  a  sui'ew  and  hand  wheel  for 
raising  and  lowering.  The  table  is  fitted  with  loose  platea,  so 
that  upon  their  i«!no|[al  It  can  be  lowered  beneath  the  spindle 
or  shaft  wliieh  carried  the  saw.  This  shaft  is  ho  arranged  that 
the  saw  can  be  taken  off,  and  either  cutter  block  and  cutters  for 
thickness  planing,  moulding  cutters  and  block  for  moulding,  c 
tenoning   block  for  cutting'  one  side   only  of  a  tenon,  can  t 


Rxed.  A  fluted  Mller  feed  ie  BxeA  on  the  liench,  and  apiings  1 
and  guides  are  used  for  thicknessing  or  moulding,  while  a  special  | 
apparatus  is  used  for  cutting  tenons.  Appliances  are  ulso  J 
supplied  to  act  as  guides  in  cross- cutting. 

The  surface  planer  has  the  cutters  fixed  by  bolts  upon  the  J 
shaft  that  carriee  the  saw,  and  the  table  of  this  is  raised  and  I 
lowered  upon  inclined  slides  by  hand  wheels.  It  is  provided  I 
with  a  movable  fence  which  can  be  set  at  any  angle  (greater  1 
than  a.  right  angle)  with  the  surface  of  the  table.  By  « 
this  fence,  and  lowering  the  front  table,  "rebating"  of  any  I 
^reasonable  dimenBionB  can  be  done.    The  left  hand  end  of  t 


166       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

spindle  is  drilled  and  provided  with  auger  bits  for  boring. 
Another  table  having  a  raising  and  lowering  movement,  and 
both  a  longitudinal  and  transverse  movement,  holds  the  material 
to  be  bored.  Special  bits  are  provided  whereby  slot  mortises 
with  circular  ends  can  be  made. 

Another  type  of  general  joiner  is  illustrated  in  Fig.  263.  The 
saw  spindle  in  this  machine  is  capable  of  being  raised  and 
lowered,  and  the  machine  will  carry  a  saw  of  any  size  up  to  20" 
in  diameter,  and  cutting  T  deep.  Tenons  can  be  cut  by  placing 
two  equal-sized  saws  upon  the  spindle  at  the  same  time,  and 
having  a  washer  between  them  to  gauge  the  thickness  of  the 
tenon.  The  shoulders  of  the  tenons  are  cut  by  two  small 
circular  saws  carried  on  vertical  adjustable  spindles  which  can 
also  be  arranged  for  carrying  cutter  blocks  and  cutters  for 
circular  moulding,  or  they  can  be  removed  easily  when  not  in 
use.  The  planing  is  done  with  revolving  cutters  ;  the  machine 
will  take  in  material  up  to  IT'  wide  and  A"  thick ;  it  can  be 
used  for  moulding  ;  it  is  provided  with  a  rising  and  falling 
table  for  thicknessing,  and  it  has  a  self-acting  roller  feed. 
Boring  and  mortising  appliances  are  also  fitted  as  shown,  a 
table  being  provided  to  hold  the  material  being  operated  upon. 

Summary. 

Handwork  in  carpentry  and  joinery  has  been  largely  superseded 
by  the  use  of  machinery. 

Sawing  is  done  with  :  the  log  frame  aaWj  which  is  arranged  to  cut 
either  horizontally  or  vertically ;  hand  saws  for  cutting  curved 
surfaces  ;  and  circular  saws  for  the  mass  of  ordinary  work.  The  saws 
are  best  sharpened  with  the  emery  wheel. 

Planing  macliines  are  classed  as  surface  planers,  thicknessing 
machines y  and  moulding  machines.  Tliey  arc  provided  usually  with 
rev^olving  cutters,  and  are  self -feeding. 

Among  other  useful  wood-working  machines  are  the  tenoning  and 
mortising  machines  and  the  general  joiner. 

Questions  on  Chapter  VI. 

1.  Compare  the  advantages  and  disadvantages  of  using  a  vertical 
and  a  horizontal  log  frame  saw  in  the  conversion  of  logs  into  boards. 

2.  Describe   the  different  types    of    band   saw,   and    state    the 
purposes  for  which  each  type  is  most  suitable. 


QUESTIONS  ON  CHAPTER  VI.  157 

3.  What  is  the  advantage  claimed  for  the  band  saw  over  the  log 
frame  saw  in  the  cutting  of  logs  into  planks  ? 

4.  Make  a  sketch  of  the  ordinary  type  of  circular  saw  bench. 
What  are  the  most  important  points  to  examine  when  selecting 
snoh  a  machine  ? 

5.  Describe  the  special  differences  to  be  found  in  the  feeding 
arrangements  of  different  types  of  circular  saw  bench. 

6.  What  should  be  the  speed  of  the  shaft  carrying  a  circular  saw 
when  the  diameter  of  the  saw  is  (a)  15  inches ;    {h)  3  feet  ? 

7.  Make  sketches  showing  the  shape  of  the  teeth  of  circular  saws 
to  be  used  when  cutting  (a)  softwood,  in  the  direction  of  the  grain  ; 
[h)  hardwood,  in  the  direction  of  the  grain ;  (c)  softwood,  across 
the  grain.     Describe  how  the  teeth  are  sharpened. 

8.  What  is  meant  by  a  "surface  planer"?  What  disadvantages 
has  this  machine  when  compared  with  other  types  of  planing 
machine  ? 

9.  Describe  the  general  arrangement  of  the  cutters  and  the 
feeding  apparatus  of  a  planing  or  moulding  machine  suitable  for  use 
in  the  preparation  of  floor  boards,  skirting  boards,  etc. 

10.  Describe  the  construction,  and  the  general  working,  of  a 
vertical  moulding  machine.  State  the  special  advantages  claimed 
for  this  machine. 

11.  Describe  the  different  types  of  hand  and  power  mortising 
machine. 

12.  Describe  briefly  the  construction,  and  fully  the  uses  of,  what 
you  consider  the  most  valuable  machine  in  a  joiner's  shop.  (C.  and 
G.  Hon.,  1897.) 

13.  Give  the  names  and  uses  of  any  machines  used  for  saving 
labour  in  a  joiner's  shop  with  which  you  are  acquainted,  and 
describe  fully  the  one  you  consider  the  most  valuable.  (C.  and  G. 
Hon.,  1893.) 

14.  Describe  the  construction  and  all  the  different  uses  of  a 
general  joiner,  and  state  how  many  men  can  work  at  it  at  the  same 
time ;  or. 

Describe  the  construction  and  uses  of  a  planing  machine  and 
of  a  spindle  machine.  N.B.  One  alternative  hxilf  of  this  qiiestion 
only  to  be  taken.     (0.  and  G.  Hon.,  1894.) 


CHAPTER  VII. 

JOINTS  AND  FASTENINGS. 

Onb  of  the  most  important  duties  of  the  carpenter  and  joiner  is 
the  fitting  together  of  timber  in  such  a  manner  that  the  com- 
pleted structure  may  have  the  greatest  possible  strength,  and 
be  as  little  liable  to  shrinkage  as  the  nature  of  the  materials 
permit.  The  methods  used  vary  considerably,  but  they  fall 
naturally  into  groups  according  to  the  underlying  principles  of 
construction.  When  the  connection  is  effected  entirely  by 
means  of  the  timbers  fitted  together,  it  is  called  a  Joint.  Most 
commonly,  however,  the  joint  is  strengthened  and  secured  by 
fastenings,  such  as  iron  dogs,  holts,  iron  straps,  coach-screiosy  keys, 
wedges,  wooden  phis,  screws,  nails,  paint,  glue,  etc. 

Principles  Governing  the  Construction  of  Joints.— Tlie 
principles  governing  the  construction  of  joints  have  been  laid 
down  by  Professor  Rankine  ^  as  follows  : 

I.  To  cut  the  joints  and  arrange  the  fastenings  so  as  to  weaken 
the  pieces  of  timber  that  they  connect  as  little  as  possible. 

II.  To  place  each  abutting  sui'face  in  a  joint  as  nearly  as 
possible  perpendicular  to  the  pressure  which  it  has  to  transmit. 

III.  To  proportion  the  area  of  each  abutting  surface  to  the 
pressure  which  it  has  to  bear,  so  that  the  timber  may  be  safe 
against  injury  under  the  heaviest  load  whi(?h  occurs  in  practice  ; 
and  to  form  and  fit  every  pair  of  surfaces  accurately,  in  order  to 
distribute  the  stress  uniformly. 

IV.  To  proportion  the  fastenings,  so  that  they  may  be  of 
equal  strength  with  the  pieces  which  they  connect. 

^ .4  ManxutZ  of  Civil  Enghxcering,  by  Prof.  Rankine.     (C.  Griffin  h  Co.) 


JOINTS  AND  FASTENINGS. 


^^^T.  To  place  the  fastenings  in  each  piece  uf  tinilwr  so  thut 
there  sliall  bo  Hiiftieient  resiHtance  t<i  the  giving  way  of  the  joint 
by  the  fnsteuings  aheajing  ur  crushing  their  way  through  the 
tinil>er. 

In  nearly  all  eases  simple  jointu  are  more  effective  than  eom- 
phcated  onex.  The  latter  ai'e  not  only  difficult  to  lit,  but  are 
very  liable  to  be  affected  by  the  shriiihage  o!  the  timber.  As 
fully  explained  in  Chap.  I.,  timber  Rhrinka  more  in  a  direction 
tangential  to  the  annual  rings  that  iwlially,  while  in  tlie 
direction  of  the  length  the  shrinkage  ie  bo  small  as  to  be 
negligible. 

Clasaiflc&tion  of  Joints.— Joints  may  be  claBsified  in  a 
general  way  as  follows  ; 

I.  Those  used  (chiefly  in  the  carpentei-'s  heavier  work)  tor 
the  lengthening  of  lieams  and  other  timbers.  These  differ  in 
airangement  according  to  the  stresses  (p.  160)  to  which  they  are 
to  be  subjected  ;  they  include  lapped,  hiilecd,  fished,  MxHtcarffi. 

II.  Those  used  for  joining  timbers  nut  in  the  same  straight  line. 
Tliis  clas^  enibraees  a  very  w^iile  range  of  joints,  including  those 
used  ill  such  heavy  carpentry  structures  as  gantries,  temporary 
statfolding,  vnoi  and  other  trusaea  and  floors,  aw  well  as  the  joints 
of  door  and  window-sash  construction,  paneiled  framing, 
drawer  construction,  etc.  These  joints  include  lap,  mortue  and 
lenon,  bridled,  notched,  eogged,  lioumd,  trenchiid,  mitred,  keyed, 
doveCailed,  etc. 

I  III.  Those  used  for  connecting  boal'ds  in   the   same   plane, 

such  ai  floor-  and  match -boarding ;  they  include  edges-ihot, 
yromed  and  lonifued,  ffrooved  and  JUleteil,  rebated,  dawdled,  etc. 
Beside  the  alxtve  there  are  quite  u  number  of  joints  which  are 
suited  U>  special  cii'uuniKtaiiceii  ;  many  cif  these  can  best  be  con- 
sidered with  the  construction  to  which  they  are  specially 
applicable. 

The  above  joints  can  best  be  studied  in  detail  under  the 
lieading  of  (1)  Carpentry  Joints,  (2)  Joinery  Joints,  although 
many  of  them  are  equally  applicable  to  botli  branches. 

tJarpentry  may  be  considered  to  embrace  the  framing  together 
of  the  rougher  and  heavier  timbers  used  in  the  construction  of 
buildings,   or   other   timber  structures  Huch  as  bridges,   spec- 
tators' stands,  centres,  etc. 
Joinery  includes  the  work  done  at  the  bench,  in  the  prepara- 
I      tisa  of  tha  flniehed  woodwoi'k  of  buildingi^  kuuV  ^a  ^neWe^ 


160      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

work  (including  doors),  window-frames,  staircases,  cupboards, 
partitions,  etc.  The  distinction  between  the  two,  if  one  need 
be  drawn,  lies  in  the  fact  that  the  carpenter  does  not  in  general 
require  to  use  the  plane  in  his  work,  whereas  the  •  joiner  works 
almost  entirely  in  wrought  or  planed  stuff.  The  timber  used 
for  joiners'  work  obviously  requires  to  be  more  thoroughly 
seasoned  than  is  necessary  with  that  used  for  carpentry. 
Timber  is  considered  sufficiently  seasoned  for  carpenters'  work 
when  it  has  lost  one-fifth  its  weight ;  for  joiners'  work  a  one- 
third  loss  is  necessary. 

Stresses  in  Beams  and  Framed  Stractures.~Beams  and 
framed  structures  when  loaded  are  subject  to  various  stresses, 
which  must  be  taken  into  account  in  arranging  the  joints 
connecting  the  members.  The  methods  of  determining  the 
amount  of  stress  in  the  various  members  of  a  framed  structure 
will  be  explained  in  Chap.  XI  [. 

h-- — ^ -^ 

J  P 

Fio.  264. — Beam  cut  to  illustrate  Stresses. 

Stress  and  Strain. — When  a  weight,  or  any  other  force,  acts 
upon  a  beam,  it  tends  to  change  the  shape  or  size  of  the  beam. 
The  force  is  technically  called  a  stress,  while  the  change  in 
shape  or  size  is  called  a  strain.  When  a  beam,  or  girder, 
supported  at  both  ends,  is  loaded,  the  upper  part  is  compressed 
and  tends  to  shorten.  The  lower  part,  on  the  other  band,  is  in 
a  state  of  tension,  as  it  tends  to  stretch.  The  force  acting  on 
the  upper  part  of  such  a  beam  is  therefore  a  compression  stress  ; 
that  on  the  lower  is  a  tension  stress. 
The  existence  of  these  stresses  may  be  made  very  apparent 
^%either  by  making  a  saw-cut  across,  or  by  actually  cutting  out  a 
wedge-shaped  piece  from,  the  middle  of  a  beam  of  wood  for 
half  its  depth,  as  shown  in  Fig.  264.  On  resting  the  beam  on 
two  supports  with  the  cut  edge  uppermost,  and  then  loading  it, 
it  will  be  seen  that  the  saw-cut  closes.  This  shows  that  the 
fibres  on  the  upper  side  are  in  a  state  of  compression.  If  the 
same  piece  is  now  turned  over  so  that  the  saw-cut  is  on  the 
lower  side,  and  again  loaded,  the  tendency  is  for  the  cut  to 
opea,  thus  showing  that  the  fibres  on  the  lower  side  are  in  a 


JOINTS  AND  FASTENINGS. 


161 


state  of  tension.  Fig.  265  gives  another  illustration  of  tension 
and  compression  stresses  ;  it  shows  three  pieces  of  timber  such 
as  might  be  used  in  a  simple  roof  truss.  It  will  be  readily 
seen  that  when  a  weight  is  placed  at  A  the  two  members  AB 


Fig.  26.0. — Truss  to  illustrate  HtresscH. 

and  AC  Ave  in  a  state  of  compression  caused  by  the  weight,  and 
tend  to  shorten,  while  the  tie  BC  prevents  the  lower  ends  of 
AB  and  AC  fvoni  spreading,  therefore  BC  is  in  tension  and  has 
a  tendency  to  stretch. 

Shearing:  Stresses. — A  shearing  stress  is  one  where  the  fibres  of 
the  wood  exhibit  a  tendency  to  slide  over  one  another.     An 


Seen  ON  on  A  B* 
Fio.  266. 


Fia.  267.— Flitched  Girder. 


example  of  this  is  shown  in  Fig.  265,  where  the  tendency  of 
the  rectangular  piece  forming  the  abutment  of  the  joint  to 
split  off  in  the  direction  of  the  grain  is  shown  at  B  and  C  by 
the  dotted  lines.  Shearing  may  take  place  with  or  across  the 
grain  ;  thus,  wooden  pins  driven  through  joints,  or  bolts  used  for 
connecting  joints  together,  are  subjected  to  shearm^  att^««»^"9». 


162       A  MANUAL  OF  CARPENTRY  AND  JOINERY.    " 

Wooden  Beams  and  Girders.— A  beam  which  spans  an 
opening  and  is  supported  at  each  end  is  known  as  a  girder  or 
bresstunmer.  Wooden  beams  may  be  used  as  girders  and  are 
often  put  in  as  "whole  timbers."  It  is  better,  however,  in 
order  to  make  the  girder  of  uniform  strength  to  proceed  as 
follows  : 

(1)  Saw  the  beam  lengthwise  down  the  middle  ; 

(2)  turn  both  pieces  so  that  the  sawn  surfaces  are  outside  ; 

(3)  reverse  one  of  the  pieces  lengthwise  so  that  the  butt  etid  of 
one  half  is  against  the  top  end  of  the  other. 

The  reasons  for  (1)  and  (2)  are  that  they  allow  of  inspection 
of  the  inside  of  the  beam,  and  the  detection  of  any .  defect  that 
may  exist ;  and  (3)  that  timber  is  stronger  at  the  lower  or  butt 
end  of  the  tree  than  at  the  top  end.     The  two  pieces  should 


I  SEcrtoM 

Fia.  268. 


Chsc/ron,  „     WrouiihtJron. 

^     toUs. 


Fig.  209. 
Examples  of  Trussed  Girders. 

then  1)0  bolted  together  at  intervals  of  from  2  to  3  feet,  with 
packing  pieces  between  them,  the  bolts  being  placed  near  the 
upper  and  lower  edges  alternately. 

Flitched  Girders.— A  girder  of  the  kind  described  in  the 
last  paragraph  is  frequently  strengthened  by  inserting  a  wrought 
iron  or  steel  plate  called  a  flitch  between  the  two  pieces  and 
bolting  the  whole  together.  The  flitch  should  be  at  least  half 
an  inch  narrower  than  the  wooden  beams,  in  case  any  shrinkage 
takes  place  in  the  latter.  Such  a  combination  is  named  a 
flitched  girder  (Figs.  206  and  267).  To  prevent  indentations 
being  made  by  the  bolts  in  the  wooden  beams,  there  should  be 
large  plate  washers  under  both  the  head  and  nut  as  shown 
in  Fig.  267. 

Trussed  Girders. — When  space  will  allow,  a  girder  is  often 
constructed  of  several  pieces  joined  to  form  a  framework  called 


JOIJITS  AND  FAerBNINOS. 


a  truBfl.     Wooden  beams  are  also  ati-engtbeued  in  vnrimis  ways 
,    by  means  of  wroiight-iron  Imlta  aud  platen  nf  wrnn^rlit  or  cast 


DatsUs  u[  iha 


and  by  wooden  or  CHut-iinn  ciimpreasion  members  called 

its.     Such  beams  are  also  called  tmsaed  girdeiB.     Figs.  268  to 

examples  cif  difl'ereiit  types  iii  trussed  git'ders.    In  Figa, 


BsmnplcB  III  TruaacsJ  Oirilcr 


id  273  tlie  bolts  shown  by  dotted  Hnea  would  b«  : 
if  the  load  welt  placed  upiin  the  lower  menibei' 

LengtheninE  of  Beams.— It    often    happens  that  wooden 
besiRB   are    inquired    longer    than    they  caa  Im  q\A»m»!4  ^:&j 


requiitd 


164       A  MANUAL  OP  CARPENTRY  AND  JOINERY. 

single  pieces.  Tlie  joint  used  fur  lengthening  such  heams 
varies  according  to  the  purpose  for  which  they  are  to  be  used, 
aa  well  as  according  to  the  stresses — tension,  compression,  or 
shearing — to  which  they  are  to  be  subjected. 

A  lapped  joint  is  formed  when  one  beam  overlaps  the  other 
(or  a  certain  distance.     If  the  beams  are  to  be  subjected  U>  a 


compression  sticss,  r  are  Iiible  to  a  cross  strain,  iron  straps 
may  be  u«ed  for  connecting  them  (Fig  2"51.  If  the  beani, 
y<hea  in  position  will  be  under  the  influence  of  a  tension  stress, 
then  Imlti  are  preftralle  (tig  274) 

"When  two  beams  abut  end  to  end,  the  ]oint  is  named  a  flsbed 
joint  and  the  cover  plates  are  called  fish-plates.  With  beanis 
"in  tension"  the  fish-plates  of  wood  may  be  sunk,  or  tabled, 
inio  the  main  beam,  aa  on  the  upper  edge  of  Fig.  277,  or  they 


JOINTS  AND  FASTENINGS. 


165 


may  have  hard- wood  "  keys  "  driven  into  trenches  cut  into  both 
beams  and  plates  as  shown  in  Fig.  278,  and  on  the  lower  edge  of 
Fig.  277.  If  iron  fish-plates  are  used,  the  ends  of  the  plate 
may  be  turned  into  the  wooden  beam  for  a  short  distance. 
This  lessens  the  stress  on  the  bolts,  but  reduces  the  strength  of 
the  beam.  Care  should  always  be  taken  that  the  indentations 
in  the  beam  are  not  opposite  each  other. 


Vw.l.  Plate 


Elevation 

Fio.  280. 


Elevation 

FiQ.  281. 


Elevation 
— ^^^^'Oak.wedffes 


Fio.  282. 
Scarfed  Joints. 


The  joints  just  described  are  all  clumsy  in  appearance,  and  in 
many  positions  would  appear  very  unsightly.  The  scarfed  joint 
is  much  neater,  though  not  so  strong.  Figs.  280  to  287  show 
different  forms  of  the  scarfed  joint.  In  the  simplest  (Fig.  280) 
each  piece  is  cut  away  for  half  the  depth  and  is  secured  by 
bolts.  Fig.  281  shows  a  very  common  form  of  scarfed  joint 
used  for  beams,  which  when  in  position  will  be  in  tension. 
The  wedges  Wj  w,  of  hard  wood  are  used  to  tighteiv  \r^  ^}cl^  \o\\A».j 


166       A  MANUAL  OP  CARPENTRY  AND  JOINERY. 

thus  rendering  bolts  unnecessary.  The  weakness  of  this  joint 
lies  in  the  tendency  of  the  triangular  pieces  ABC  to  shear  off. 
The  maximum  strength  is  secured  when  the  length  of  AB  is 
about  seven  times  that  of  DB.  Stronger  scarfed  joints  are 
shown  in  Figs.  282  and  285.  Such  scarfed  joints  are  suitable 
for  beams  which  are  to  be  subjected  either  to  tension  or  to 
compression  stresses.  The  length  of  the  scarf  will  depend  upon 
the  material   used ;    the  length  may  be  diminished,  and  the 


B 


Z 


^ 


OaJcK^s 


B 


Elevation. 

Fig.  285. 


Fio.  280. 


Fio.  287. 


Scarfod  Joints. 


strength  of  the  joint  increased,  by  using  fish-plates  and  bolts. 
Fig.  283  is  a  sketch  of  the  cut  end  of  one  beam  of  the  joint 
shown  in  elevation  in  Fig.  282.  Fig.  284  is  a  corresponding 
sketch  of  Fii(.  285.  Scarfed  joints  of  a  design  suitable  for 
resisting  ci'oss-stress  and  tension  are  shown  in  elevation  in 
Figs.  280  and  287.  ^ 

Halving. — Halving  (consists  of  cutting  the  ends  of  each  piece 

to  half  the  depth  and  securing  with  either  bolts,  nails,  screws, 

or  wooden  pegs.     A  halved  ioint  is  one  of  the  simplest,  and  is 


JOINTS  AND  FASTENINGS.  187 

verj  suitable  for  connecting  beams  thnt  have  to  be  joint«d  on 
the  top  of  a  post,  or  that  hava  some  other  niejina  of  support ; 
for  croHS  rails  meeting  on  a  post  or  other  support ;  for  wall- 
plates  resting  on  the  wall  ;  for  long  I'idge -pieces,  etc  Figs. 
iai  and  393  show  typical  examples. 


^  i    I    I  'M    £ 


-J— 


-J- 


FiQ.  ass.— "BuUt-up"  Beam. 

Keying, — Wooden  keys  are  pieces  of  hard  wood  used  either  to 
connect  two  piec^  together,  or  with  bolts  to  prevent  the  pieces 
from  sliding  over  each  other.  Although  very  long  wooden 
iieaciis  are  now  nekloiu  used  for  carrying  purposes,  having  been 
largely  superseded  by  iron  or  steel  girdei'a,  it  in — as  has  been 


said— occasionally  necessary  to  construct  beams  of  greater 
length  than  can  be  obtained  in  one  piece.  Fig.  288  shows  the 
elevation  of  a  beam  which  is  built  up  of  foui'  pieces  connccte<I 
by  bolts  and  having  hard. wood  keys  iusei'ted  to  prevent  the 
pieces  fromwliding  over  each  other.  Fig.  '289  illustrates  what 
in  known  as  a  hamiii'T-headeil  ley.  Tliis  key  is  tightened  up 
with  small  wedges  ( 11',  11')  aa  shown. 


168       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

Joints  for  connecting  Timbers  meeting  at  an  Angle.— This 
class  of  joint  requires  to  be  arranged  so  that  the  abutment  is  as 
nearly  as  possible  at  right  angles  to  the  pressure.  It  embraces 
all  the  joints  in  roof  and  other  truss  construction,  and  although 
many  of  these  can  best  be  considered  in  detail  with  the  particular 


Fio.  2'.)4 


Fig.  295. 


structures  with  which  they  are  connected,  some  typical  examples 
will  now  be  explained. 

Halving. — Halved  joints  are  used  also  for  connecting  timbers 
at  an  angle.  Figs.  290  to  29;")  are  examples  with  the  distinctive 
name  of  each  appended.  A  halved  joint  may  be  secured  with 
either  bolts,  nails,  screws,  or  wooden  pins. 

Housing. — Housing  consists  of  letting  bodily  into  one  piece  the 
end  of  the  other  piece  which  has  to  be  connected  to  it.  Fig.  296 
jshows  in   elevation   the   lower  end  of  a  post   housed  into   a 


JOINTS  AND  FASTENINGfi. 


169 


cross  rail.     Thin  joiut  in  also  sometiiiiea  called  a  uatched  Joint, 

especially  when   light   pieces  are   thus   tminected  to  »   heavy 

beam.     The  ceiling  joist*  of  a  room 

usually   are    notched  to  the   main 

girders  of  a  floor  above.    The  ends 

of  a  wooden  cistern  are  often  housed 

into  the  sides. 

Lappm^. —Beams  are  "often  built    ..., p- 

up  of  a  number  of  thicknesses  of        ;  I 

material  with  the  joints  across  each      "' ~ TTl "" 

,,  „,,  ■      .  -  ,,      ,.  Fio.  21H).— Housed  Joint. 

other.     This  is  especially  the  case 

with  the  curved  ribs  of  a  roof  truss,  or  the  curved  ribs  of  a 

wooden  centre.     Such  built-up  beams  are  secured  with  either 

nails,  screws,  bolts,  or  wooden  pegs.    They  will  be  more  fully 

explained  in  a  later  chapter. 


HortlH  and  teoon  joint. — In  its  varied  forms  this  joint  is 
ii.<ed  perhaps  more  extensively  than  any  other.  In  carpenters' 
work  the  mortise  and  tenon  may  be  the  only  means  by  which 
the  two  parts  are  connected,  or  they  may  be  used  simply  for  the 
purpose  of  keeping  the  joint  in  position. 

Tlie  proportions  and  the  sliapo  of  the  tenon  vary  considerably, 
but  when  used  wholly  for  connecting,  the  tenon  ia  ltto\v\  ot*- 


170       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

fourth  to  one-third  the  thickness  of  the  material,  and  the  bearing 
power  of  the  joint  depends  upon  the  accuracy  with  which  the 
shoulders  fit  the  piece  containing  the  mortise.  Fig.  297  shows  a 
sketch  of  a  mortise  and  tenon  joint  with  the  names  of  the  different 
parts  given.  A  joint  of  this  description,  when  used  for  connect- 
ing purposes,  should  have  a  width  of  tenon  of  not  more  than  five 
times  the  thickness  ;  and  the  outer  side  of  the  mortise  should  be 
a  little  longer  than  the  inner  or  shoulder  side,  to  allow  of  wedges 
being  driven  into  the  end  of  the  tenon  to  fasten  it  securely. 
Such  joints  are  often  fastened  by  driving  the  wedges  into  the 


Section  through  A .  B. 


fi 


Plan 


Fig.  298. — Haunched  Tenon  Joint. 


Fio.  299.— Double  Mortise  and  Tenon 
Joint. 


space  left  between  the  edge  of  the  tenon  and  the  end  of  the  mor- 
tise. This  method,  however,  has  a  tendency  to  make  the  tenon 
narrower  at  the  outer  end,  and  to  some  extent  to  defeat  the 
object  aimed  at  ;  if  two  saw-cuts,  one  near  each  edge,  are  made 
in  the  tenon  before  it  is  put  into  position  (Fig.  297),  and  the 
wedges  are  driven  into  these  saw-cuts,  they  spread  the  outer  end 
of  the  tenon,  making  it  wider,  and  thus  securely  fixing  it  in 
position.  When  a  tenon  is  reduced  in  width,  either  by  cutting 
off  one  or  both  edges,  oi*  by  cutting  a  part  out  of  the  middle,  or — 
as  is  the  case  when  a  mortise  and  tenon  joint  is  used  where 
two  pieces  meet  at  an  angle  (Fig.  298) — it  is  called  a 
haunched  tenon.  Figs.  642  and  643  show  types  of  the  haunched 
tenon. 

A  barefaced  tenon  is  one  that  has  the  tenon  flush  with  one  side 
of  the  material  (Fig.  642),  and  has  therefore  only  one  shoulder. 


JOINTS  AND  FASTENINGS. 


171 


--I 


-1— B 


SECTION  through  A  B . 
Fio  300.— Tusk  Tenon  Joint. 


In  many  kinds  of  framing,  the  thickness  of  the  material  is  so 
great  that  a  single  tenon  of  the  usual  proportion  would  unneces- 
sarily weaken  the  piece  containing  the  mortise,  and  therefore 
two  tenons  are  arranged 
side  by  side  as  shown 
in  Fig.  299.  Such  tenons 
are  known  as  double 
tefiions. 

Another  type  of  mortise 
and  tenon  joint  used  in 
carpenters'  work, arranged 
to  weaken  the  timbers  as 
little  as  possible,  is  the 
tusk  tenon  joint.  This 
joint  is  much  used  in 
floor  and  roof  construc- 
tion. The  tenon — which 
usually  has  a  thickness  of 
one-sixth  the  width  of  the 
material — is  strengthened 
at  the  root  by  projections 
left  on  at  the  shoulder.  These  projections,  known  as  the  tusk, 
are  of  the  proportions  shown  in  Fig.  300,  which  should  be 
noticed   carefully.      In  some  cases  (as  for  example  the  joints 

of  floor  joists)  the  tenon 
projects  through  and  be- 
yond the  surface,  and  is 
secured  with  a  wedge  which 
passes  through  a  small  mor- 
tise made  in  the  tenon,  as 
shown.  When  this  jcrtnt  is 
used  with  large  beams  the 
Fio.  30i.-Skotch  of  a  Tusk  Tenon  Joint,  mortise  extends  about  half- 
way through,  and  a  wooden  pin  is  driven  through  the  tenon. 

In  addition  to  the  tenon,  the  joint  in  Fig.  302  has  what  is 
known  as  a  cross-tongue  on  each  shoulder.  Tliis  method  of 
strengthening  the  joint  may  be  used  in  all  cases  where  the 
tenon  cannot  be  conveniently  of  the  usual  proportions.  Cross- 
tongues  are  cut  out  of  hard  wood  in  such  a  way  that  the 
grain  of  the  tongue  runs  in  the  same  direction  as  that  of  the 
tenon. 


"iencm/ 


172      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


In  order  to  give  additional  strength  to  the  joint,  the  end  of 
ihe  piec-e  bearing  the  tenon  ie  itaelf  frequently  sunk  (houBed) 


ther  piece  for  a  shoi't  distance,     Thi8  armngameiit 
n  a  mortised  and  housed  joint  (Figs.  303  and  304). 


Fox-itedging  is  a  device  adopted  for  8eciii-ing  a  niortiae  and 
tenon  joint  wliei-e  the  joint  cannot  be  weilged  from  the  outside, 
or  where  the  tenon  does  not  go  through  the  piece,  aa,  for 
example,  in  the  case  of  a  post  fixed  against  a  wall,  or  of  a  aill 
resting  on  a  Soar.     In  these  and  similar  contingenciex  the  length 


JOINTS  AND  FASTENINGS.  173 

of  the  mortise  is  greater  inside,  that  is,  tbe  enda  are  cut  eloping, 
and  Baw-cutB  are  made  in  the  end  of  the  tenon.  When  the  joint 
is  being  put  together,  wedges  are  carefully  inserted  in  the  saw- 


cula,  and  when  the  joint  is  forced  together  the  wedges  spread 
the  outer  ends  of  the  tenon  (Figs.  305  and  306). 

This  method  of  fox-wedging  is  also  suitable  for  superior  work, 
where  the  appearance  of  the  end  of  the 
tenon  on  the  edge  ot  the  framing  would 
be  considered  objectionable. 

In  the  dovetailed  tenon  one  edge  of 
the  tenon  is  cut  obliquely  {tplayed),  and 
the  length  of  the  inortiae  is  made  a  little 
greater  than  the  width  of  the  tenon. 
The  joint  ia  secnred  witha  wedge  which 
is  driven  into  the  space  left  on  the 
straight  side  of  the  tenon  (Figs.  308 
and  309). 

A  ckaie  morlise  is  used  at  one  side  when  a  cross-piece  has  to 
be  inserted  and  fixed  with  mortise  and  tenon  joints  between  two 
beams  already  fixed.  Fig.  3t0  shows  the  mortise  chased  out  so 
that  the  croaa-piece  can  be  pushed  into  position. 


10. —Chase  Mortising. 


174       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


A  stump  or  stub  tenon  is  a  short  tenon  usually  employed  more 
for  the  sake  of  keeping  the  joint  in  position  than  as  a  means  of 
connection.  It  is  used  extensively  for  the  joints  ux  large  and 
heavy  trusses,  as  will  be  seen  by  referring  to  Chapter  IX., 
dealing  with  them. 

Bridle  Joint. — The  bridle  joint  is  the  converse  of  the  mortise 
and  tenon  joint.  In  bridle  joints  the  middle  part  of  one 
member  is  cut  out  so  that  it  will  fork  on  to  the  other  member, 
which  is  suitably  cut  to  receive  it.  Generally  the  bridle  joint 
can  be  fitted  more  accurately,  weakens  the  material  less,  and 
makes  a  stronger  joint ;  it  is  therefore  preferable  in  heavy 
carpenters'  framing — where  the  members  meet  at  an  acute 
angle,  as  in  Fig.  432, — to  the  stump  tenon,  although  the  latter 
is  possibly  more  generally  used. 

Joggle  Joint. — In  a  joggle  joint,  a  projection — the  joggle — is 
left  on  the  end  of  a  wooden  post  which  is  intended  to  fit  into  a 
stone  or  wooden  sill  (Fig.  307).  The  sill  itself  contains  a 
suitable  mortise  cut  to  receive  the  joggle. 

Cogged  Joint. — A  cogged  joint  is  one  where  two  pieces 
are  partly  sunk  into  each  other  in  order  to  minimise  space. 
Examples  are  to  be  seen  in  floor  construction,  where  the  floor 
joists  are  cogged  on  to  the  binders  or  on  to  the  wall  plates  ;  or 
in  I'oof  construction,  where  the  purlins  (p.  216)  are  cogged  on 
to  the  backs  of  the  prmcipal  rafters.  It  will  be  seen  from 
an  examination  of  Figs.  ^90  and  391  that  in  the  cogged  joint 

f  each  piece  is  cut  in  such  a  way 
that  the  material  is  not  appreciably 
weakened. 

Fastenings     for     Carpenters' 
Joints.  —  Much   heavy    carpentry 
consists    of   the   building  of  such 
temporary    structures  as   scafibld- 
ing,   shoring,   gantries,   temporary 
wooden  buildings,  spectators'  stands, 
bridges,  and  the  like.     As  the  tim- 
ber in   these   is   after  use   still   a 
marketable  commodity,  and  as  the 
connections  or  joints  are  best  made 
as  simple  as  possible,  the  iron  dog  and  the  cleat  are  both  much 
used.     A  dog  is  a   wrought-iron  fastening  of  varying  length, 
having  the  ends  ))ointed  and  shaped  as  shown  in  Figs.  31 1  and 


Iron  Dogs. 


r 


.TOINTS  AND  PASTKNINGR. 


It  is  very  necessary  to  have  the  pntnted  eniis  at  an  iirigle 
little  gi'eatfir  than  ft  right  angle,  bo  that  as  they  are  driven 
into  the  lonterial  they  will  tend  to  draw  the  joint  together. 
By  their  use  the  need  to  make  either  mortise  and  tenon,  or 
hridle  joints,  is  largely  reduced,  as  the  doga  prevent  the  meni- 

liei'a  from  moving  laterally.     Cleats  nre  short  pieces   of  wood. 

which   are  either   bolted   or  nailed  against   heavy   timbers  to 

HHslst   in   forming   an   abutment   for  a  Joint.      They    may,   in 

addition  to  being  l«ilted,  be  housed  for  a 

ahoit  distance  into  tiio  beam  to  which  they 

are  fastened. 
BdltB  ai'e  made  of  the  Iwst  wrought  iron 

They  have  a  head  of  variable  shape  at  one 

end,  the  other  end  being  threaded  and  fitted 

with    a    nut   for    tightening- up    purposes 

Square  bolts  are  better  than  round  ones  for 

juints  in  tension.     To  prevent  the  nut  from 

sinking  into  the   fibres  of  the  wood  when 

tightening    up,    washers — small    plates    of 

wrought  iron — are  placed  between  the  nut 

and   the    material.      In    heavy   structure':, 

waaher*  should  also  be  placed  under  the 

lead  of  the  bolt,      SmaU  circular  washers 

a.tii  used  generally,  but  it  ia  better  to  use 

larger  plate  washers  having  a  thickijesR  of 

one  half  times  the  diameter  of  the  bolt. 
Stmpe.— Bolts  may  be  used  alone  or  they 

may    be    used    along     with     wrought-iron   pm.  Bia.— Coach-Mmw. 

|)lates,   or   straps,  for  connecting  jointa   in 

timber  structures.     Tlie  straps  may  be  of  almost  any  shape  : 

atruight,  bent,  thi*ee-way,  or  four-way,  and  are  geueially  used 

in  pairs,  one   being  placed  on   each   side   of   the  joint   to   be 

connected.  They  are  pierced  by  a  number  of  holes  through 
^^glii'Jh  the  bolts  are  passed.  It  frequently  happens  that  the 
^^^bpe  are  made  to  clip  the  material  and  are  therefore  U-shaped, 
^^^^b.  the  case  of  the  fastening  of  the  lower  end  of  a  king  post 
^^RQi  a  atrnp  and  gibs  and  cotters  (Fig.  434).  Stra,ps  may  be 
^^Mured    with     coach -screws    instead    of    bolts.      Coacli-«orewB 

fFig,  313)  are  of  wrought  iron,  with  a  square  flat  head,  and 

have  a  coarse  screw-thread  which  passes  between  thf  fibre,*  of 

aw.maofl.    ffHien  holts  are  uHed,  the  liolea  m_^ 


176       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

should  be  as  nearly  as  possible  of  the  same  size  as  the  bolt ; 
but  with  coach  screws  the  holes  should  be  a  little  less  than  the 
diameter  of  the  screw,  to  enable  the  screw  to  hook  into  the 
fibres  and  thus  get  firm  hold  of  the  material. 

Joint  lK>lts  are  another  type  of  bolt  used  for  connecting  the 
joints  of  wooden  structures.  They  are  chiefly  used  where  two 
pieces  meet  at  a  right  angle,  and  where  a  strap  would  be 
unsightly  or  in  the  way.  A  joint  bolt  is  circular,  has  a  square 
flat  head,  and  is  screw- threaded  for  a  much  greater  distance  than 
an  ordinary  bolt  for  the  purpose  of  drawing  the  joint  together. 
The  threaded  end  is  also  pointed  to  enable  it  more  readily  to 
catch  the  nut,  which  is  of  rectangular  shape,  larger  than  the  nut 
of  the  ordinary  bolt,  and  requires  letting  into  one  of  the  pieces 
to  be  connected  (Fig.  439).  Another  type  of  joint  bolt  used  for 
connecting  the  ends  of  two  pieces  together  is  threaded  at  both 
ends,  one  end  being  provided  with  a  rectangular  nut,  and  the 
other  with  a  circular  nut  with  grooves  in  its  edge.  Joint  bolts 
are  sometimes  provided  with  an  extra  long  thread  which  is 
screwed  into  the  end  of  the  material  like  a  coach  screw,  the  nut 
being  dispensed  with. 

It  is  a  wise  precaution  in  heavy  carpentry — the  joints  of 
which  are  connected  with  bolts — to  examine  the  structure 
some  time  after  it  has  been  completed,  and  tighten  up  where 
necessary,  as  the  wood  of  such  structures  is  not  always  properly 
seasoned  at  the  time  of  framing  together. 

To  preserve  iron  fastenings  from  oxidation  they  may  be 
galvanised,  dipped  while  hot  into  pitch,  or  they  may  be  painted 
with  oxide-paint.  If  iron  fastenings  are  used  for  unseasoned 
oak,  the  gallic  acid  contained  in  the  oak  will  cause  rapid  oxida- 
tion, and  discolour  the  wood.  '  It  is  therefore  occasionally 
necessary  to  use  copper  or  other  metal  fastenings  with  such 
wood. 

Wedging  and  pinning. — As  already  explained  in  the  description 
of  the  mortise  and  tenon  joint,  wedges  play  an  important  part 
in  fastening  the  joints  of  woodwork.  The  wood  from  which 
they  are  made  should  be  dry,  straight-gi'ained,  and  fairly  hard, 
and  the  wedges  themselves  should  not  have  too  much  taper. 

Wooden  pins  should  be  of  hard  wood,  straight-grained,  dry, 

and  should  be  split  rather  than  sawn  to   the   I'equired   size. 

Square  or  rectangular  pins  are  not  so  liable  to  become  loose, 

and  are  therefore  better  than  circular  ones.     If  properly  fixed, 


JOINTS  AND  FASTENINGS. 


177 


Nufc 

Washer  j 


Fio.  314. — Lewis-  or  Rag-bolt. 


they  may  be  made  a  very  secure  means  of  connecting  a  joint. 
A  good  method  of  fixing  a  wooden  pin  to  connect  a  mortise  and 

tenon,    or    a    bridle 

joint  is  to  bore  the 

hole    in    the    centre 

piece  a  little  distance 

nearer  the  shoulder, 

so  that    the  pin   in 

being     driven     into 

position      will,      by 

pressing  against  the 

fibres(Fig.  298),  draw 

the    joint    together. 

This  method  is  named 

di*aw  horinig.     Large  wooden  pins  are  sometimes  called  trenails. 
Framing  exposed  to  the  weather  is  preserved,  and  the  wedges, 

pins,  or  other  wooden  fastenings  adhere  better,  if  a  paint  con- 
sisting of  white  and 

wypT^r {    red  lead  and  linseed 

oil,    mixed     to     the 
consistency  of  thick 

Lead    or^  \zj^^^SSS^^     !    ^^^^'^•i  is   used  as  a 
Brimstone 


coating  for  all  parts 
of  the  joint  which  are 
in  contact. 

For  fixing  wood- 
work against  stone 
or  brick-work  many 
expedients  are  em- 
ployed. A  lewis-  or 
rag-bolt  is  often  used. 
This  consists  of  a  bolt 
which  has  a  specially 
shaped  head,  let  into 
a  dovetail-shaped 
hole  made  in  the 
stone,  and  fastened 
thereto  by  means  of 
lead  or  brimstone  (Fig.  314).  The  other  end  of  the  bolt  is 
screw-threaded  and  provided  with  a  nut  and  washer. 
Sldit-UllB,    known    also   as    snipe-bills,  are   iroT\.  VoVMasX^e* 


il 


r 

I . 


Fig.  315. 


Pio.  816.— 8plit.bm. 


178       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


(Fig.  316)  let  into  the  stone  work  at  the  head  end,  the  points, 
which  pass  through  the  wood  work  to  be  secured,  being 
**  clenched."     Iron  holdfasts  of  many  other  shapes  are  also  used. 

These  are  driven  into  the  joints  of 
the  stone  or  brick  work  only  ; 
or,  which  is  preferable,  wooden 
plugs  are  first  driven  into  the 
joints  and  the  holdfasts  are 
driven  into  these. 

Wooden  plugB  should  be  cut  out 
of  dry  straight-grained  wood,  and 
they  hold  more  securely  if  cut 
with  the  axe,  with  a  little  twist 
on  each  surface  (Fig.  317,  -B),  than 
if  they  are  cut  with  the  saw  with 
straight  surfaces  (A),  The  hole 
into  which  a  plug  has  to  fit  should  be  first  made  and  then  the 
plug  cut  so  that  the  small  end  will  just  fit  the  hole.  The  plug 
should  fit  the  hole  accurately  for  at  least  two  inches  (Fig.  317,  B). 

Nails  are  too  well  known  to  need  more  than  a 
brief  description.  Nails  may  be  obtained  in  any 
length  from   14  inches   down  to  ^  inch.      The 


Fio.   317.— Method  of  fixing 
Wooden  Wedges. 


Fk;.  318.— Wrought 
Spike. 


Fio.  310.— Cut 
Clasp  Nail. 


Fio.  320.— Wrought 
Clasp  Nail. 


Fio.  321.— Brad, 


largor  ones,  often  called  spikes,  are  only  used  in  very  heavy 
work  to  a  limited  extent,  as  anything  that  requires  a  nail  longer 
than  six  inches  will  be  better  fastened  with  a  bolt  or  a  coach 
screw.  Spikes  should  be  forged  out  of  the  best  wrought  iron, 
and  be  of  the  shape  shown  in  Fig.  318. 
Clasp  nails  are  of  size  from  six  inches  downwards,  and  may 


JOINTS  AND  FASTENINGS. 


179 


l>e  cut  or  wrought.  "Cut  clasp"  are  those  which  are  cut  out  of 
aheet  metal  aud  are  of  shape  shown  in  Fig.  319.  "Wrought 
tiasp"  are  tougher  than  the  cut  oaila;  they  are  used  where  the 
nail  pasaea  through  botli  the  pieces  to  he  connected,  and  the 
points  are  folded  over  (clenched).  The  head  ot  eufh  kind  of  nail 
ia  shaped  so  that  it  can  be  driven  readily  below  the  eui-face. 

Brads  are  cut  nails  of  shape  shown  in  Fig.  321  :  the  aliape  of 
the  head  is  such  that  when  the  nail  ia  driven  below  the  surface 
the  I'eanlting  hole  is  very  small.  Brads  are  used  for  securing 
floor  hoards,  and  the  smaller  varieties — culled  sprigs — for 
eecaring  mouldings,  etc.,  in  position. 

Wire  nails  are  much  used  in  fixing  woodwork.    They  are 


^ 


ought 


ciade  in  a  variety  of  shapes,  and  in  all  sizes  from  six  inches  to 
Ulf  an  inch  in  length.  The  round  ones  with  flat  heads  (Fig. 
3SS)  ore  used  for  such  purposes  as  packing-case  making,  fencing, 
hoartlings,  and  all  kinds  of  rough  carpentry.  The  oval  shaped 
(Fig.  323)  are  much  used  instead  of  the  cut  clasp  for  the  mass  of 
ordinary  work.  Wire  nails  square  in  section  are  also  obtain- 
able,  but  are  not  so  much  used  as  the  other  varieties. 

Clout  naili  are  wrought,  and  have  round  heads.  They  are 
used  for  securing  sheet  metal,  hoop  iron,  I'oofing-felt,  etc.,  to 

Wroitffit  naiU  of  shape  shown  in  Fig.  326  are  extensively  used 
by  the  coach-builder  and  sliip-builder  ;  they  are  stronger  than 
the  ordinary  cut  nail,  but  are  seldom  used  by  the  carpenter. 

Tucks  are  small  nails  pointed  at  one  end,  and  have  a  round., 


180       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


Fig.  326.  Fio.  827. 

Types  of  Screw. 


Screws. — Screws  are  used  more  by  the  joiner  than  by  the 
carpenter.    They  may  be  of  wrought  iron  or  of  brass.    Figs.  326 

and  327  show  typical  screws  with  flat 
and  round  heads  respectively.  The 
heads  of  screws  ai*e  of  various  forms, 
such  as  flat,  round-headed,  square,  hexa- 
gon, and  of  many  ornamental  designs. 
For  securing  woodwork  the  flat  headed  is 
mostly  used.  The  other  shapes  are  used 
chiefly  for  securing  metal  fastenings  to 
wood  work,  and  to  give  them  an  orna- 
mental appearance.  Screws  are  obtain- 
able in  all  sizes,  of  both  length  and 
diameter,  to  six  inches  long.  When 
screws  are  used  for  securing  removable 
wood  work,  they  should  be  provided  with  sockets  which  are  let 
into  the  wood. 

JOINERY. 

Although  the  work  of  carpentry  and  of  joinery  differs  enough 
to  justify  a  separate  classification  of  the  joints  used  in  the  framing 
together  of  the  various  structures,  it  is  impossible  entirely  to 
separate  them,  even  if  it  were  thought  advisable  to  do  so.  In  the 
same  way  no  hard  and  fast  distinction  can  be  drawn  between 
the  work  of  the  carpenter  and  that  of  the  joiner.  It  is  true 
that  in  large  works  some  men  are  exclusively  confined  to  joinery 
as  "  bench  hands,"  while  others  are  engaged  as  "  fixers  "  on  the 
building,  or  are  employed  in  setting  up  carpenters'  work.  It  is 
advisable,  however,  that  the  workman  should  have  a  good  all- 
round  knowledge  of  both  branches  of  the  work,  as  it  is  only  in 
large  workshops  that  such  specialisation  can  be  attempted. 

Many  of  the  remarks  in  the  early  part  of  this  chapter  will 
apply  to  the  joints  in  joinery,  especially  those  relating  to  the 
mortise  and  tenon  joint,  as  the  bulk  of  the  panelled  framing 
of  doors,  partitions,  cupboards,  etc.,  as  well  as  the  joints  of 
such  framing  as  sashes,  are  of  this  type. 

The  timber  used  for  joiners'  work  requires  to  be  more 
thoroughly  seasoned  than  is  necessary  with  that  used  for 
carpentry.  Greater  care  is  also  necessary  in  arranging  the 
joints,  so  that  any  slight  shrinkage  shall  not  be  visible.  Much 
of  the  material  for  joiners'  worjc  is  now  prepared  by  machinery. 


JOINERY. 


181 


In  the  joints  of  door  and  sash  framing  many  special 
modifications  of  the  mortise  and  tenon  joint  are  necessary.  In 
panelled  framing,  for  example,  the  groove  into  which  the  panel 
fits  reduces  the  width  of  the  tenon ;  while  in  sashes  the 
rebate  for  the  glass,  and  the  moulding  of  the  arrises,  affect 
the  shape  of  the  shoulder.  These  points  will  be  considered 
in  detail  along  with  the  constructions  to  which  they  respec- 
tively refer. 


Bead( 


Single^uirkecL 

Fio.  328. 


"1 


QuiriP 


Double  qiurked^ 
Staff  bead 

Fio.  829. 


DoubfpquJ/M 
riiis^Lbead 

Fio.  330. 


Code  bead 
Fio.  331. 


FiUet 


Wet 


FULet 


I 


Cbckbea^Litfiilet 
Fio.  332. 


Roman-  Ovolo. 
Fio.  333. 
Types  of  Mouldings. 


Cavelto  orHoliov/' 

l?lo.  334. 


Mouldings. — The  arrises  of  joiners'  work  are  often  orna- 
mented by  mouldings.  It  is  necessary  to  consider  these  since 
they  influence  the  making  of  the  joint.  The  curves  in  Boman 
mouldings  are  segments  of  circles,  while  in  Greek  mouldings 
parabolic  and  elliptical  curves  predominate.  Roman  mouldings 
are  built  up  from  the  types  shown  in  Figs.  333  to  337.  The 
distinctive  name  is  in  each  case  indicated  on  the  sketch. 

Bead  or  astrag^al — Various  forms  of  this  moulding  are  shown 
in  Figs.  3S28  to  332.  The  difference  between  the  quirked  bead 
(Fig.   328)  and  double-quirked  or  stag   bead  (^V^.  "Xi^^  ^"^A 


182       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

between  the  Jlush  bead  (Fig.  330)  and  the  cock  bead  (Fig.  331) 
should  be  particularly  noticed.  The  bead  is  extensively  used 
at  the  joints  of  boarding,  to  counteract  the  unsightly  appear- 
ance that  might  be  caused  by  any  slight  shrinkage.  It  is 
also  much  used  as  an  angle  moulding.  When  a  number  of 
flush  beads  are  worked  together  on  the  same  surface,  as  in 
Fig.  342,  a  reeded  moulding  is  obtained.  Fluting  (Fig.  341) 
is  the  converse  of  reeding. 


Fig.  835. 


Torus  moultJU 
Fio.  338.     • 


FULcL 


Filiet 


Vgee  or  C^ma,  recta^ 
Fig.  836. 


Fio.  339. 


^Reverse  Otjee>  or- 
(^nuv  re*nsrseu 

Fig.  337. 


Jfoidded///bsUt^ 
Fig.  340. 


Fig.  341. 


PeecUna 
Fig.  342. 


Types  of  Mouldings. 


Torus. — In  this  moulding  (Fig.  338)  the  diameter  of  the  bead 
is  vertical.  It  is  surmounted  by  a  flat  projecting  part  called 
a  filet. 

Lengthoning  joints. — This  class  of  joint  is  not  required  to 
the  same  extent  in  joinery  as  in  carpentry.  It  is  seldom  that 
tlie  scarfed  joints  are  resorted  to,  and  lapped  and  fished 
joints  are  still  less  frequently  used.  The  halved  joint  may 
be  used  with  advantage  sometimes,  while  the  hammer  headed 
key  (Fig.  368)  Ls  very  suitable  for  securing  curved  ribs 
thfit  form    the   head   of    a  semicircular    door-frame   or  large 


JOINERY. 


183 


window-frame,  or  any  other  circular  framing  of  like  nature. 
Such  joints  may  be  strengthened  by  inserting  either  cross- 
tongti£s  of  hard  wood  as  shown  in  Fig.  368,  or  short  wooden 
dowels.  The  splayed  joint  is  used  for  connecting  the  ends  of 
mouldings,  skirting  boards,  etc.,  which  are  in  long,  straight 
lengths.     Other  lengthening  joints  are  shown  in  the  chapter 


Fio.  343. 


Tonffited Joi/rt 


Fig.  844. 


fiebatni  Jtbeaded 
Fig.  345. 


RelmJed  int/y 

rcJAirii  heAJLCt 

Pig.  346. 


Jlousai  iirtrcnc/iea 


Fio.  347. 


Toiigueti  trenrhtxf 
Fig.  348. 


MoveUuted  trejtche^ 


FiQ.  349. 


Fio.  850. 


^rass-tongut 


Fig.  851. 


Mitred  Angle  joints. 
Fig.  352.  Fig.  353. 


Fig.  354, 


on  floors,  where  floor  boards  meet  on  a  floor  joist.  Such  joints 
are  called  heading  Joints  ;  they  may  be  square  edged,  rebated, 
splayed,  tongued  and  grooved,  or  forked,  although  the  diflft- 
culty  of  construction  in  the  last-named  is  not  compensated  foi* 
by  the  additional  advantage  it  possesses.  A  form  of  joint  used 
iu  connecting  hand-rails,  is  a  butt-joint ;  in  forming  it  two 
hard  wood  dowels  are  inserted,  and  a  small  joint-holt  with  a 
nut  at  each  end, .  as  shown  in  Fig.  892,  is  used  ;  such  a  bolt 
is  called  a  handrail  bolt. 


184       A  MANUAL  OF  CARPENTRY   AND  JOINERY. 


Angle  Joints. — Fig.  343  is  the  simplest  joint  for  connecting 
together  two  boards  meeting  at  an  angle.    Figs.  344  to  346  show 


of  thia  form  of  joint.     Figs.  347  to  3S0  are  sectiona 

through  difTerent  forms  of  trenched  joints.    The  first  of  these 

might  also  be  called  a  housed  joint ;  it  is  the  one  used  in 

staircase    construction    where    the 

;         steps    are   housed   into   the   notch 

[         boards. 

I  Uitrlug   and  Boiltdiiff. — In  cases 

„       yi  '    -  /■     *'i**'^  '*  '^  undesirable  to  show 

'-'  the  end  grain  of  the  wood,  mitring 

is  employed.     Figs.  351  to  354  are 

sections  through  various  kinds  of 

mitred  joinU.    When  two  lengths 

')--9?4  °^  ''^^  same  moulding  meet  at  an 

-  "TT  angle,  as,  for  exaniple.at  the  corners 

ot    an    ai'chitrave    surrounding    a 

door  or  a  window  opening,  or  in 

any  mouldingx  meeting  at  an  angle,  the  joint  always  bisects 

the   angle,   and   is  called  a   mitred   joint   (Fig.  356).      Under 

certain  conditions  it  is  better-  to  cut  the  end  of  one  moulding 

to   fit   the  profile   of  the  other   as   shown   in   Fig.  357.     This 

plan  fs  called  »eribing.     Other  examples  of  these  two  joints 


JOINERY.  ISfi 

are  found  in  the  skirting  board  that  vane  round  a  room.  . 
The  external  angles  are  mitred ;  the  internal  angles  are 
beet  Bcribed.  The  method  of  cutting  the  lower  edge  of  a 
Bkirting  board  to  fit  the  slight  irregularities  of  the  floor 
(instead  of  tonguing  the  board  to  the  floor)  is  also  known 
as  scribing. 

CT0BB'gTOOv\ag — The  joint  shown  in  section  id  Fig.  344  ma; 
also  be  applied  in  the  manner  shown  in  the  sketch  (Fig.  358), 
as,  for  example,  at  the  corners  of  boxes  or  cisterns.     The 


^crihedjoi 


FiQ.  SfiS. — Ctvea-grooving. 


groores  into  which  the  tongue  fits  is,  when  it  runs  across  the 
grain  of  the  wood,  an  example  of  cross-grooving. 

Dovetailine.— Figs.  349  and  350  are  sections  of  dovetailed  joints. 
Pig.  359  is  a  sketch  of  the  common  form  of  ungU  dovetail  joint 
where  two  boards  meet  at  an  angle.  This  is  the  strongest  kind 
of  angle  dovetailed  joint.  It  can  only  be  used,  however,  when 
there  is  no  objection  to  the  end  grain  of  the  wood  being  visible. 
The  lap  dovetail  (Fig.  360)  is  so  arranged  that  the  joint  on  one 
face  ia  not  visible.  It  is  useful  in  such  work  as  the  construction 
of  drawers.  The  mitred  or  lecret  dovetail  joint  (Fig.  361 )  is  not 
so  strong  as  either  of  the  others,  hut  is  used  when  it  is  desired 
to  hide  the  joint  coqipletel/. 


186       A  MANUAL  OF  CARPENTRY  AND  JOINERY- 


£4ge  Joints. — Boards   having  their  edges   planed   straight 
And  true  are  aaid  to  have  their  edgM  B&ot. 


^Tan^Hed.&  Grooved    A 


Angle  DovQtail  Jolnta, 

Mfttch-boarilliM:.— Timber,  however  well  aeaaoned,  has  always 
a  greater  or  leas  tendency  to  shiink  ;  aod  this  renders  it  in- 
advisable to  use  wide  boards  in  covering  surfaces  of  large  area. 
Tn  superior  worii, 
panelled  framing  is 
extensively  adopted, 
ut  alterna- 
tive method  is,  how- 
ever, to  use  boards 
of  batten  width,  with 
square,  grooved  and 
tongued,  or  rebated 
edges.  This  class  of 
boarding  is  known  as 
•match  -  hoarding.  In 
Fig.  363,  which  is  a 
cross-section  of  such 
tongued  -  and  ■  grooved 
battens,  the  tongued 
edge  of  each  batten  is 
beaded.  This  serves  the  double  purpose  of  destroying  the 
monotony  of  the  surface,  and  of  hiding  any  slight  shrinkage 
that  ma.j  take  place  in  the  biiai'ds.     Tt  is  evident  that  if  some 


JOINERY. 


187 


such  means  of  treating  the  joint  were  not  adopted,  as  is  the 
caae  in  Fig.  362,  any  shrinkage  would  produce  an  unaightly 
appearance.  Instead  of  being  beaded,  the  edges  are  often 
chamfered,  as   in    Fig.    364.      This    treatment    is    known    as 


V-jointing.  Examples  of  the  use  of  match-boarding  are  seen 
in  wainscotting,  and  also  in  boarded  ceilings.  Wide  panels 
in  framing  are  often  constructed  of  match-boarding. 

Edge  Joints  for  irlde  boardB. — If  a  wide  board  is  required,  the 
teodency  to  warping  is  diminished  if  it  is  composed  of  several 
pieces  so  jointed  together  that  the  heart  sides  of  alternate  pieces 


Fio.  366.— Secret  acrewcd  Joint. 

ire  reversed  (Fig.  365).  If  glue  is  used  and  the  work  is  for 
a  dry  position,  the  edge  joints  may  be  square.  Alternative 
methods  are  to  tongue  and  groove  the  edges,  to  groove  both 
edges  and  insert  a  lath  or  fillet  of  hard  wood  (grooved  and 
filleted  joint),  or  to  dowel  the  joint  by  inserting  wooden  pegs 
of  haH   wood  at  intervals  of  12"  to  18"  apart. 

Another  method — although  it  is  not  applicable  to  very  thin 
boards— ia  to  turn  strong  screws  into  the  edge  ot  one  "p\ftce. 


189      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

and  after  boring  holea  into  the  edge  of  the  other  piece,  to 
make  chases  to  allow  the  head 
of  the  screw  to  hook  between  the 
fibres  and  thus  hold  the  joint 
together.  These  screws  may  be 
placed  anywhere  from  one  to 
two  feet  apart.  Fig.  366  illus- 
trates this  joint. 
Table  or  R«le  Joint— Pig.  367 
riQ,  m;.— Tabio  or  Ruia  Joint.  '^  *  section  of  a  rule  joint. 
This  joint  is  used,  along  with 

hinges,  where  the  edges  of  two  hoards  move  upon  each  other 

through  an  angle.      Good  examples  are  found  in  Bume  types 

of  window  shutters  (Fig. 

793),  the  leaves  of  a  fold- 
ing table,  etc. 

Keying    and   Clamp- 
ing.—The  panels  used  in 

framing,  as  well  aa  thin 

wide    boards  which    are 

liable  to  warp,  are  some- 
times    strengthened     by 

the  insertion  of  tapering 

dovetailed    ieye    of    hard 

wood.    These  are  placed 

at  right    angles    to    the 

grain  of  the  wood  of  the 

boards,  as  shown  in  Fig.    O'OSS' 

369.    Clampliw  serves  the   tongi.  e 

same  purpose  as  keyinij. 

It  consists   of   arranging 

narrow  pieces  along  each 

end  of  the  board,  so  that 

the    grain     shall     be    at 

right  angles  to  the  grain 

of  the  boards,  as  shown 

in  Fig.  370.     The  clamp 

may  either  have  a  tongued 

and  grooved,  a  do  welled, 

or    a     square     joint,    or       , 
it    may    be    made    with 


JOINERY. 


189 


mortise  and  tenon  joints.    Fig.  370  shows  one  of  the  clamped 
ends  mitred. 

Glue  and  Glue- 
blocks. — Glue  is  used 
by  the  joiner  as  an 
aid  in  securing  joints. 
Glue  is  made  by  boil- 
ing, straining,  and  re- 
boiling  the  skins  and 
bones  of  animals. 
After  being  thus 
treated  the  material 
is  cut  into  cakes  and 
dried.  Glue  made 
from  skins  is  stronger 
than  that  made  from 
bones.  Its  quality 
also  depends  largely 
upon  the  care  be- 
stowed in  the  boiling 
and  straining.  The 
appearance     of    dark 

blotches  in   the  cakes     ^i^  Pio.  359. 

is     a    sign     of    poor 
quality.      Freshly  mixed  glue  is  by   far  the  best ;    repeated 
heating  decreases  its  strength.     Glue  should  be  used  as  hot 


Pig.  370.— Wide  Board  with 
Clamped  Ends. 


as  possible,  and  the  surfaces  to  which  it  is  applied  should  be 
perfectly  dry  and  even  warmed.    Glue  should  not.  Vye  too  >;XiV^  \ 


190       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


the  thinner  the  layer  applied,  so  long  as  the  whole  surface  is 

covered,  the  better  will.it  adhere. 

When  preparing  glue,  it  is  best  to  break  up  the  cake  into 

small  pieces,  place  them  in  a  jar  with  just  sufficient  water  to 

cover  them,  and  soak  for  several  hours. 
The  glue  is  afterwards  melted  by  being 
placed  in  the  upper  pan  of  the  glue 
pot,  the  lower  pan  of  which  is  filled 
with  water.  The  glue  is  softened  by 
the  heat  from  the  water  in  the  lower 
pan,  sufficient  clean  hot  water  being 
added  to  the  glue  to  render  it  of  the 
right  consistency.  It  is  ready  for  use 
when  it  runs  freely  off  the  glue  brush 
without  breaking  into  drops.  Glue 
capable  of  withstanding  the  weather 
may  be  made  by  adding  powdered 
chalk  to  ordinary  glue. 

Olue-blocks  are  short  pieces  of  wood 
that  are  glued  into   the  angles  to  aid 

in  strengthening  joints.      They  are  much  used  by  both  the 

joiner  and  the  cabinet-maker.     Fig.  371  shows  an  example  of 

glue-blocks  in  position. 


Fio.    371.  —  Example    of 
Glue-blocks. 


Summary. 

The  main  principles  underlying  the  construction  of  Joints  are  : 

To  have  each  abutting  surface  at  right  angles  to  the  pressure 
upon  it,  and  of  area  proportional  to  the  pressure : 

To  arrange  fastenings  so  that  they  caimot  weaken  the  pieces  they 
connect. 

Joints  are  most  commonly  used  for  connecting 

(1)  beams  in  the  same  straight  line  ; 

(2)  beams  making  an  angle  with  each  other  ; 

(3)  boards  in  the  same  plane. 

A  stress  is  any  force  producing  a  change  of  shape  or  size ;  the 
change  of  shape  or  size  produced  by  a  stress  is  called  a  strain. 

A  girder  or  bressummer  is  a  beam  spanning  an  opening  and 
supported  at  both  ends.  Girders  may  bo  of  wood  only  (solid  and 
rectangular) ;  flitchod  with  an  iron  plate  ;  or  trussed. 

Beams  are  lengthened  by  lapped,  scarfed,  halved,  or  keyed  joints. 


SUMMARY.  Idl 

Timbers  at  an  angle  are  connected  by  halved,  housed,  lapped, 
mortised  and  tenoned,  bridle,  or  cogged  joints. 

Fastexdngs  for  joints  include  iron  dogs,  cleats,  bolts,  vyrought  iron 
stra/ps,  joint  bolts,  coa^h  screws,  wedges,  pins,  nails,  screws,  and  glue. 

Woodwork  is  fastened  to  brick  or  stone  work  by  nails  driven 
into  wooden-plugs,  or  by  leuns  or  rag-bolts,  by  split  bills,  etc. 

In  Roman  mouldixigs  the  curves  are  segments  of  circles ;  in  Greek 
mouldings  parabolic  and  elliptical  curves  predominate. 

Other  forms  of  angle  Joints  more  common  in  joinery  are  rebated, 
tongued  and  grooved,  mitred,  scribed,  and  dovetailed. 

The  edge  Joints  of  boards  in  the  same  plane  may  be  grooved  and 
tongued,  rebated,  or  grooved  and  filleted. 

Boards  may  be  strengthened  across  the  grain  by  Tceying  and 
clamping. 

Questions  on  Chapter  VII. 

1.  What  is  meant  by  cambering  beams?  Why  is  it  done? 
Describe  flitching  and  trussing  girders,  and  illustrate  your  answer 
by  sketches.  Draw  six  forms  of  scarfed  joints,  and  state  the 
purposes  for  which  they  ^ire  used.     (C.  and  G.  Ord.,  1901.) 

2.  A  fir  beam  9  in.  by  6  in.  and  14  ft.  between  supports,  is 
insufficient  to  carry  the  load  upon  it.  Explain  and  sketch  three 
various  ways  in  which  it  might  be  strengthened.  (C.  and  G.  Ord., 
1«96.) 

3.  It  is  required  to  lengthen  three  beams  (each  10  in.  by  6  in.), 
one  of  which  (a)  is  to  be  used  in  compression,  one  {b)  in  tension, 
and  the  other  (c)  in  cross  strain.  Draw,  one-quarter  full  size,  the 
methods  of  scarfing  you  would  adopt.     (C.  and  G.  Ord.,  1894.) 

4.  Show  by  sketches  the  different  methods  of  scarfing,  and  state 
which  are  adapted  for  the  different  strains.    (C.  and  G.  Ord.,  1898.) 

5.  Make  isometric,  or  oblique,  projections  of  one  of  the  following 
joints  ;  (a)  dovetail  halving ;  (6)  simple  mortise  and  tenon.  (C. 
andG.  Ord.,  1899.) 

6.  Draw  the  oblique  or  isometric  projections  of  the  following 
joints  : 

(a)  Bare  faced  tenon  joint. 

(6)  Double  tenon  joint. 

(c)  Common  dovetail  joint. 

{d)  Dovetail  tongue  and  groove  joint.     (C.  and  G.  Prel.,  1904.) 

7.  {a)  Make  sketches  of  a  tusk  tenon  joint.  Timbers  9  in.  by 
3  in.  Mark  on  the  dimensions  of  the  several  parts,  {b)  What 
proportion  should  the  tenon  bear  to  the  thickness  of  the  material 
used  in  joiners*  work  ?    (C.  and  G.  Ord. ,  1899.) 


Id2      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

8.  Under  what  conditions  are  haunched  tenons  used  ?  State  the 
usual  proportions  of  the  width  and  the  thickness  of  the  tenon  in  a 
mortise  and  tenon  joint.  Mention,  and  state  the  reasons  for,  any 
exceptions  to  the  usual  proportions. 

9.  Make  a  sketch  of  each  of  the  following  types  of  mortise  and 
tenon  joint,  and  show  in  each  case  how  the  joint  is  fastened : 
haunched,  dovetail,  tusk,  and  stump  or  stub. 

10.  Make  a  sketch  of  an  iron  dog.  Give  an  illustration  of  the  use 
of  iron  dogs  and  cleats  as  a  suitable  means  of  fastening  timbers 
together. 

11.  Make  sketches  to  illustrate  three  different  methods  of 
fastening  a  vertical  wooden  post  to  a  stone  wall. 

12.  Make  sketches  of  the  following  mouldings :  Cyma-recta 
(Roman  and  Greek),  Astragal  torus  (Roman  and  Greek),  Cavetto 
(Roman  and  Greek),  Ovolo  (Roman  and  Greek).  These  drawings 
must  be  large  enough  to  show  the  geometrical  construction,  and  the 
working  lines  should  be  left  in.     (C.  and  G.  Ord.,  1898.) 

13.  Draw  6  different  joints  used  by  joiners,  and  give  their  names 
and  uses.     (C.  and  G.  Ord.,  1902.) 

14.  Draw  the  isometric  or  the  oblique  projections  of  the  following 
joints : 

(1)  Lapped  dovetailing  joint  for  drawer  front. 

(2)  Haunched  mortise  and  tenon  joint.     (C.  and  G.  Prel.,  1902.) 

15.  (1)  Make  a  sketch  of  a  secret  dovetail  joint,  and  (2)  show  two 
methods  of  securing  and  finishing  the  exterior  angle  of  dado 
framing.     (C.  and  G.  Ord.,  1903.) 

16.  A  wide  board,  IJ  in.  thick,  has  to  be  constructed  (with  glued 
joints)  out  of  three  separate  boards.  Show  by  sketches  three 
different  suitable  methods  of  making  the  edge  joints. 

17.  State  the  precautions  necessary  to  observe  when  preparing 
and  using  glue.  How  would  you  judge  its  quality?  Give  an 
illustration  to  show  the  use  of  glue-blocks. 


CHAPTER  VIIL 

WOODEN  FLOORS. 

Types  of  Wooden.  Floors. — Wooden  floors  are  constructed 
by  placing  on  edge,  planks,  deals,  or  battens  called  Joists,  from 
12"  to  15"  apart,  and  on  the  top  of  these  securing  the  boards 
which  form  the  surface  of  the  floor.  In  upper  floors,  the  joists 
carry  on  their  undersides  either  the  lath-and-plaster  ceiling,  or 
the  ceiling  joists  to  which  the  laths  and  plaster  are  fixed. 
When  the  distance  between  the  walls  which  support  the  ends  of 
the  floor  joists  is  not  more  than  16  feet  the  joists  may  be  placed 
80  that  they  stretch  from  wall  to  wall  without  intermediary 
support.  A  floor  so  arranged  is  named  a  single  floor.  With 
spans  of  greater  distance  than  16'  it  would  be  essential,  in  order 
to  obtain  the  necessary  rigidity  of  such  a  floor,  to  have  unwieldy 
joists  of  large  section.  Besides  involving  a  waste  of  material, 
such  joists,  not  being  of  the  usual  marketable  sizes,  are  more 
expensive  and  difficult  to  obtain.  It  is  therefore  more  economi- 
cal to  use  lighter  joists,  and  support  them  with  cross-beams. 
Floors  so  arranged  are  named  double  or  ftumed  floorB,  according 
to  the  arrangement  of  the  timbers. 

Dimensions  of  Joists. — The  carrying  strength  of  a  joist,  or 

other  beam,  is  proportional  to  the  fraction     -v—  where  d  is  the 

depth  in  inches,  b  the  breadth  in  inches,  and  L  the  length  in 
feet.  From  this  expression  it  will  be  seen  that  of  two  joists 
of  the  same  length  and  sectional  area,  the  one  of  greater 
depth  will  be  the  stronger.  For  example,  the  relative  strengths 
of  two  joists  12"  deep  by  2"  broad,  and  8"  deep  by  3"  broad 
respectively  (i.e.  of  the  same  sectional  area,  24  square  inches), 
will  be  as  12x12x2=288,  and  8x8x3  =  192,  that  la^^-.'i. 


194       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

In  pmctice,  a  limit  is  set  upon  the  aikrrowneBB  b^  the  neces^ty 
of  nailing  boards  to  the  joists  without  splitting  the  latter, 
and  it  is  usual  to  have  the  depth  from  three  to  four  tines 
the  breadth.  To  prevent  the  buckling  of  narrow  joists,  strut- 
ting ia  employed. 

Dwelling-house  floors  are  made  strong  enough  to  carrj  about 
li  cwte.  per  square  foot  of  floor  surface ;  while  the  floors  of 


Plin  and  Section  of  H  Single  Floor. 

warehouses,  etc,  subject  to  heavy  loads,  are  capable  of  bearing 
from  l^-  to  3  cwts.  per  square  foot.  The  calcuhitions  necessary 
to  determine  the  size  of  the  timbers  are  dealt  with  in  Chapter 
XII.,  but  a  useful  rule,  genei-ally  applicable  to  dwelling-houses, 
is  to  have  the  depth  of  ilie  joists  (in  inches)  e(]Ual  to  half  the 
span  (in  feet)  plus  2. 

Single  Floors. — Aa  already  explained,  single  floors  are  those 
the  joists  of  which — called  bridging  Joists — stretch  from  wall  to 
wa}L    Single  floors  are  generally  suitable  for  dwelling-bouses, 


WOOIfflV  FLOORS.  1K5 

the  diviaii  n  walk  serving  to  nujjjjfit  the  eiid^  of  the  joiBts. 
It  la  obviuua  th  it  the  strongest  Ituor  is  obtained  by  placing 
the  joints  acroKs  the  shortest  way  of  any  room  which  la  not 
sq^uare  in  plan,  althoU[;h  the  joi'^ts  should  liv  preference 
hA\a  the  ends  leiting  on  the  outer  walls  latliet  than  upon  the 
pirtj  walla  that  dmde  one  home  from  another  Figa  373  and 
373  shuw  plan  and  section  of  a  amgle  floor. 

Instead  of  having  the  plasterers'  laths  nailed  to  the  under- 
side of  the  joists,  floors  are  sometimes  tonatfiioted  which  have 
every  third  or  fourth 

]      t    lout  2    leeper  |\!\  at*"'* 

than    he      st ;    and 

malle  ]  sta,  called 
ceUing'  Jolits  ahout 
3  4    hy   2     are 

fl    d  la       dtr 

B  de  of  these      These 

elig  jn,t,  c  , 
11  e    plaster    ce  I 

prevent    e  f  o  a 

^n      to      ,noll         ""*! 
When  wocden  fl  ora 
are  used  aa  grou  d 
fl  nrn,  and  there  is 

noVaaementorcelU         p  o  3  i -Mko  Ui  of  part   tuBrtka-op     WbI 
underneath        t      la 

essent  al  that  an  air  upate  of  at  lea  t  I  6  be  1  ft  under  the 
floor  and  that  the  ground  under  au  h  i  floor  be  co  ered  w  th 
a  layer  of  concrete  f  om  4  to  th  ck  In  a  floor  of  th  a 
descnpt  on  the  depth  of  the  ]0  ta  iiay  be  mate  allj  reduced 
by  support  ng  then  at  ntervals  of  5  or  (  ty  sleeper  walls  of 
h   ck  nr  stone  (P  g  3  4; 

Ciound  floors  onstru  te  1  of  n  I  are  I  able  to  the  d  sease 
kuown     s  rf  y  rot  unless  precaut  ona  a  e  adopted  to  h     e  the 

pace  well  ventUtel  between  the  undera  de  of  the  floor  and 
the  grn     d  and  th    II  or  ]0  st'i  veil  suaanned  befo  e  le  ng  fixed 

Wall-plates. — ^Tlie  enda  of  floor  joiats  may  rest  on  wall- 
plates,  which  are  lengths  of  timber  ahout  4^"  wide  and  3"  thick, 
W^-|)latea  ehould  also  be  used  ut  any  inteTmeduitiB  '^tno.tA  oi 


support,  such.  aB  those  of  sleeper  walla.     As  A  preftirablu  substi- 
tute for  a.  wall-plate  when  joists  ara  built  into  tlie  wall,  aa  iruii 
bar  aj"  wide  and  J'  thick  may  be  kid  in  the  wall  for  the  enda 
of  the  joists  to  rest   upon.     This  bar  is  not  so  liable  to 
destroyed,  by  damp  or  other  agency,  as  a  wooden  wall-plat*. 


How  the  enda  of  JoistB  Bhould  rest. — The  ends  of  joists, 
in  basement  tloors,  should  not  be  built  into  the  wall,  but 
should  rest  oji  ofiati,  which  are  formed  by  having  the  walla 
thicker  below  the  ground  floor.  These  offsets  are  frequently- 
obtained  in  buildingH  several  storeys  high  by  diminiBhing 
the  thickness  of  the  wall  at  tha 
floor  levels  (Fig.  375).  Where  offaeU 
are  inconvenieut,  an  altornative 
method  of  carrying  joists  is  obtained 
by  building  projecting 
bricks,  as  shown  in  I'ig.  376.  These 
are  named  OTei-saUlSK  counei,  and  tha 
arrangement  is  known  as  ooTtadUiig. 
The  projection  required,  about  4^",  is 
obtained  in  thl'ee  or  more  courses,  and 
supports  the  wall-plate.  The 
object  can  be  attained  by  using  Htoiie  corbels  built  into  th» 
walls  at  horizontal  distances  of  2'  to  3'  apart,  and,  if  necessary, 
using  thicker  wall-platea  (Fig.  377). 

Although  offsets  and  corbelling  cannot  generally  be  used  for 
supporting  the  upper  floors  of  dwelling-houses,  it  is  ecTpeciolly 
advisable  to  adopt  one  of  these  inetlioiis  for  carrying  the  upper 
wooden  Soare  of  large  wnrebouaas,  workdMpB,  v 


WOODEN  FLOORS.  IflT 

I,  tlie  middle  part  of  the  flour  might  be  first 
dftatroved,  and  the  remainder  would  then  act  as  a  lever  when 
there  wjuld  be  con 
siilemble  daiiger  of 
the  walls  being  o\pr 
thrown  The  joiits 
may  rest  on  the  wall 
plates  aa  in  }<ig  3'b 
be  iu)li,hed  oil  aa  m 
Fig.  377  or  theviiiM 
be  coqqed,  as  ahoun 
in  Fig  375 

When  ]oiste  are 
built  into  the  wall,  an 
air  spate  of  at  least 
lialf  an  inch  should  be  A 
left  along  the  sides 
and  above  each  joiat, 
to  prevent  decay 

Trimming  —  Nn 
beajing  tmilier  hIuimIiI 
be  plated  nearei  thrfji 
six  inihes  to  a  chimn<^v 
f)ue.  This  necessitates 
an  arrangement  of 
framing  the  flooi  j  usta 
whiL^h  IS  named  Inm 
mijig.  In  tiimniini, 
the  bridging  j  nwti 
whioh  would  ibiit 
against  the  fine  iri. 
supported  liv  a  trois 
piece  called  a  trimmer 
TLe  joists  which  carij 


the 


!nda  of  the 
lallLil 
It  m 


ir  and  the  trimming  joiats  thicker 
tliai!  the  luidging  joists  by  J  for  every  budging  joist  carried. 
Fig.  378  shows  the  trimming  of  the  joiata  around  a  fiveijlaHft, 
Trimming  n  aho  iieccsaai  v  for  stiirc  ise  weUa,  Ira.'p  ioo'ct,  o 


198       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


A 


— B 


any  opening  in  a  floor  which  is  wider  than  the  space  between 

two  joists. 
Joints  used  in  Trimming. — The  form  of  joint  mostly  used  in 

trimming  is  the  tusk-tenon  Joint    This  joint  is  specially  designed 

to  prevent  unnecessary 
weakening  of  the  timbers. 
As  explained  on  p.  171, 
the  thickness  of  the  tenon 
is  one-sixth  the  depth  of 
the  joist,  and  the  lower 
surface  of  the  tenon  is  in 
the  centre  of  the  depth. 
The  tusk  (Figs.  379  and 
380)  extends  into  the  joist 
for.  a  distance  equal  to 
one-flfth  the  thickness  of 
the  joist.  The  joint  is 
secured  by  allowing  the 
tenon  to  project  through 
the  mortise,  and  inserting 
a  wedge  into  a  small 
mortise     made     in     the 


Section  through  A  B . 

Pig.  879. — Tusk-tenon  Joint. 


tenon.      These  aie  omitted  where  they  would  be  in  the  way, 
as  in  the  joint  between  the  trimmer  and  bridging  joists. 

The  ordinary  mortise  and  tenon  joint,  with  a  thickness  of  tenon 
about  .one-fourth  the  depth 
of  the  joist,  is  often  used  and 
secured  with  wedges,  but  is 
not  so  strong  as  the  tusk- 
tenon  joint.  Housed  Joints,  as 
shown  in  Figs.  381  and  382, 
are  alternative  methods  often 
adopted.  These  are  usually 
secured  with  sj)ikea  (large 
nails). 

Hearth-Flags  and  Trimmer  Arches. — When  a  fireplace  occnrs 
in  an  upper  room,  it  is  necessary  to  have  a  hearth-flag  from  3'  6* 
to  5'  long,  and  projecting  at  least  18"  from  the  front  of  the  fire- 
place. The  flag  may  be  supported  by  a  concrete  slab  built  into 
the  brickwork,  and  projecting  so  as  to  fill  the  space  left  between 
the  trimmer  and  the  brickwork ;  or  l)y  a  brick  arch  known  as 


— ftWWf 


tUSi 


Fio.  380. — Sketch  of  a  Tusk-tcuon  Joint. 


WOODEN  FLOORS. 


IT  arch,  which  springs  on  one  side  from  the  brickwork 
Jand  on  the  ot.liei-  fram  the  tcinnnei'.     Fig.  373  shows  plan  and  a 


vertical  section  of  a,  fireplace,  the  hearth-flag  of  which  ia  carried 
hy  a  bnclc  tmomer  arch      The  upper  half  of  the  plan  Bhowa  tlie 


jMrtit-flag,  floor-boaTda,  etc.,  in  position  ;  in  the  lower  part  of 
*        "   Biff  grcfe  snd  joista  are  Bhown.    Buc\  kci  ot^ 


.hroi^h  13 


a»      A  MANUAL  OF  CARPENTRY  ATTO  JOTNERY. 

is  named  a  coavh-headed  trimmer  ai'cli.  Fig.  383  is  a.  Hketoh  of 
tbe  same  tirepluiK,  showing  the  oonstruotion  still  more  cleitrlj. 
Ab  aa  alternative,  the  trimmer  arch  may  abut  square  on  tlie 
trimmer,  as  shown  ia 
section  ill  Fig,  384 
TL  i  s  is  necessary  when 
the  joists  are  not  mora 
than  seven  inches 
deep.  When  the 
bridgmg  joists  are 
placed  parallel  to  the 
fireplace,  aa  shown  in 

ming  joist,  which  ia 
the  one  agaiant  which 
the  ai-ch  will  abut,  ia 
Htrengthened,  and 
prevented  from  yield- 
r  Arch,  i^S  ^y  ^^  inaertion 
of  two   holta,   which 

hook   into   the   brickwork   at   one  end  and  pass   thi'ough  the 

middle   of   the   depth   of    the    trimming    joist    as    shown 

Tigs.  384  and  392.     A  narrow  margin,  often  of  oak,  is  generally 

mitred  around    the    three 

sides   of   the    hearth-flag;  f:»f.v«r*«<a^gjj«^ 

against  it  the  lioor-boai'ds 

abut.  Tiles  of  various  kinda    ' 

are  often  substituted  for  a 

hearth-dag. 
Bridging    and     Stmt- 

ting, — Wooden    floors    are 

Etrengthened    by    placing 

rows  of  kemng-bone  lirid/j- 

iiig   or   ttnttting    at    right 

angles  to  the  direction  of 

the  joists,  and  at  distances 

of  i'  to  5'  apart.     This  strutting  is  formed  by  pieces  of  timber, 

about  2"  by  Ih",  crossing  each  other,  and  nailed  to  the  joists  in 

the  manner  shown  in  Figs.  373  and  385,     An  alternative  plan  ia 

that  known  as  iolid  atnUting.     Solid  strutting  consists  of  fising  ' 
of  short   boards   on  ei\g6   ti^liUy  between    the    joists  . 


WCWDEN  FLOORS. 


201 


(Fig.  386.)  Such  Ixmi-dB  are  one  infh  narrower  tlinu  the  deiith 
of  the  joiatH  and  fmui  1"  tii  Ij'  thiek.  When  solid  strutting 
ia  adopted,  the  fluor  may  be  further  sti-engthened — 

(a)  By  passing  a  three-quarter-iiitli  bolt  through  the  centre 
of  the  depth  of  the  joiata,  close  againat  the  strutting,  thiie  bind- 
ing the  whole  together  (Fig.  383) ; 

(6)  by  nailing  hoop  iron  (ij"  to  2°  wide,  and  one-aiiteenth 
of  Mt  inch  thick)  along  the  top  and  bottom  edges  of  the  joists 
where  the  strutting  is  fixed,  and  then  tightening  up  the  struts 
by  means  of  wedges. 

Sound-boaxding  and  Fogging.— This  name  is  given  ta  a 
darice  adopted  to  prevent  the  piisaage  of  sound  from  a.  i-oom  to 
the  one  below.     It  ooiisiats  of  laying  a  floor  of  rough 
abort  boards  about  half-way  down  the  depth  of  the         j? 
joiatB,  and  resting  on  fillets,  shaped  as   in    Fig.  387,         '^ 
■which  are  nailed  on  both  sides  of  each  joist.     These 
lioards   carry  rough  mortar,  often  mixed  witli  ashea  or  Raw- 
dust  (Fig.  386)  i  or  &  layer  of  silicate  cotton  or  slag  wool  to  a 


^epth  of  2"  or  3"  may  be  sulwtituleil,     Tlie  rough  luortar,  etc., 
is  named  piiifgitui. 

Double  PIOOTB, — Double  flooi's  have  beams  or  binders  pliiced 
ftjom  6' to  10' apart.     On  theM  reat^the  brid^ng  joiste  w^^^l 


202      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


carry  the  floor  boards.  In  double  and  framed  floors  the  weight 
of  the  whole  floor  is  concentrated  on  a  few  points,  namely,  the 
ends  of  the  binders  and  girders.  This  may  be  an  advantage 
when  there  are  many  window  openings,  or  where  the  wall  can  be 
strengthened  by  piers ;  but,  since  the  floor  timbers  help  to  bind 
the  walls  together,  a  single  floor  does  this  more  effectively,  as 
the  joists  distribute  the  weight  more  equally  on  the  walls. 
Again,  double  floors  take  up  a  greater  depth  than  single  floors, 
and  thus,  by  requiring  higher  walls  for  the  same  height  of 
rooms,  increase  the  cost  of  buildings.  Double  floors  are,  how- 
ever, most  suitable  for  rooms 
from  16'  to  24'  wide.  Figs. 
388  and  389  show  plan  and 
section  of  a  double  floor. 

In  order  to  reduce  the 
depth  of  the  double  floor 
without  materially  affecting 
its  strength,  the  joists  are 
usually  cogged  on  to  the 
binders,  as  shown  in  Figs. 
390  and  391.  The  distance 
that  the  joists  are  cogged  on 
to  the  binders  may  be  any- 
thing up  to  two-thirds  the 
depth  of  the  joist.  As  the 
upper  edge  only  of  the  binder 
is  cut  and  the  joists  fit  tightly 
into  this,  and  as  there  is  a  full  bearing  for  the  end  of  the  joist, 
it  will  be  seen  that  a  little  extra  depth  of  cogging  does  not 
seriously  weaken  the  joint. 

Ceiling  Joists. — When  a  plastered  ceiling  is  required  on  the 
underside  of  a  double  or  framed  floor,  the  plasterers'  laths  may 
be  nailed  to  the  underside  of  the  bridging  joists,  and  the  beams 
either  wrought  and  their  arrises  moulded,  or  be  "  firred  out " 
for  the  plasterers'  laths  :  that  is,  have  strips  of  wood  2"  by 
I"  nailed  at  distances  of  from  12"  to  15"  apart  on  the  three 
sides  that  i-equire  to  be  plastered. 

If  it  is  desirable  that  the  beams  be  hidden  so  that  the  ceiling 
shall  be  in  one  plane,  ceiling  joists  3"  to  4"  deep,  and  2"  thick 
may  be  fixed  in  one  of  the  following  ways  : 
(a)  be  notched  to  the  underside  of  the  binder  as  in  Fig.  390  ; 


Fig.  390. — Sketch  showing  Cogged  and 
Notched  Joints. 


^itgugrf^fragm^i7iM'rjpari^^ 


WOODEN   FLOORS. 

(6)  be  cut  to  fit  between  the  I  Inilurs  and 
wood  named /Z/b!s  (Fig.  391) 

(c)  have  short  tenoiia  fol  lued 
with  corresponding  nioili-iea  c 
method  in  adopted  tlie 
hinders  are  "  chased  out 
at  one  side  to  allow  one  end 
of  the  ceiling  joiate  to  bu 
placed  into  position  after 
the  bindere  are  fixed  (Fig 
391).  Mortises  so  cut  are 
named  cMae  mortuet  and 
are  seldom  used. 

Flamed  Floors,— Framed 
floors  are  occasionally  used  where  the  distance  hetneen  the  nalla 
ia  over  24' and  it  ia  not  desirable  to  hate  any  pillan 
A  framed  floor  consists  of  girdei-a,  binders,  bndgini;  joists,  floor 
boards,  and — when  a  plaster  ceiling  la  required— ceiling  joists. 


i 

^^d^ 

-Girder 

■y/)h  V 

\ 

L 

...  -  wV--- 

\ 

/y-7A 

^i'4M/-m. 

Space /be  M 

Vm.  Se2.— Plau  o[  a  Framed  Fl 


Fig.  392  shows  the  plan  of  a  framed  floor  with  part  of  it«  mrface 
covered  with  floor  boards.  Muny  of  the  bridging  joists  a 
omitted  in  tiiis  illustration  for  the  sake  of  clearness.  The 
trimming  of  the  joists  for  a  fireplace  and  for  ii  staircase  well 
is  shown.  In  the  fireplace-trimming,  the  trinimiiig  joist 
siiuwii  to  have  t«'o  bolts  coniieoting  it  to  the  brick  woik  tg 
assist  the  ubiitnieot  of  the  arch. 


entirely  with  wooden  beams  the  binders  which  are  carried  bj 

the  girclei'<i  are  tusk  tenoned  into  them,  as  shown   in   Fig.  393. 

Such  a  joint,  bo«e\ei,  weakens  the  girder  considerably,  and  a 

stronger  connection   can  be  made  bj  resting  the  binder  in  a 

cast  iron  shoe  or  stirrup,   having  a  small   projection   behind, 

which    is    let    into    the 

beam.    Tlie  stirrup  itself 

is  secured  to  the  girder 

with   coaeh   screws.     Fig. 

395     shows 

stiiTup   in   position 

girder     Wrought 

^l*^)      often      used 

stiiru])'?  ;   Fig.  396 

niple.      - 

irmed  that  Pitched 
and  trussed  girders  (Figs. 
266  tn  273)  are  often  used 
an  the  heavy  beams  of 
fi-Liaed  floors. 
Pillars  or  OolumnB. — A  modihcatmn  of  the  framed  floor  just 
described  is  often  adopted  for  buildings  of  large  span.  This 
consists  in  arranging  the  floors  in  bays  of  from  8'  to  12*  wide,  the 
ends  of  the  bridging  joists  of  each  bay  being  cogged  on  to  the 
girders,  which  have  intermediate  supports^in  the  shape  of 
pillara  (coiurana)  of  wood,  cast  iron,  or  steel — when  more  than 
25'  long.  By  using  coluiiiiis  in  this  manner  the  size  of  the 
jfirdera  is  .reduoed. 


WOODEN  FLOORa 


fCaat  iron  oolamnB,  wliich  are  nifiat  frequently  used,  are  hollow 
cylindei-M,  with  a  thickness  uf  iiietal  of  from  ^"  to  IJ".     'J'he  lower 


ends  of  these  columns  reat  either  on  large  foundation  stones  o 
upuQ  a   base  of  concrete,  and  the  upper  ends  have  a,  head  o 


Fio.  m-.~Caat  Iron  Cnli 


206      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

vertically  over  each  other,  a  cast  iron  beam-box,  which  spans 
the  beain,  may  bo  used  to  support  the  lower  end  of  the  upper 
column.  Another  plan  is  to  allow  the  upper  column  to  fit  into 
the  upper  end  of  the  lower  one,  the  head  or  seating  of  the 
lower  column  being  large  enough  to  support  the  floor  girders. 


Figs.   397   and  398  show   examples   of   the   heads   of   columns 
supporting  floor  girders. 

The  Use  of  Wrought-Iron  and  Steel  Girders  in  Floor 
Construction, ^Wrougl It  iron  and  Btecl  girders  have  in  recent 
years  largely  superseded  heavy  wooden  beams  for  floor  con- 
struction. Although  the  former  are  stronger,  and  not  so  liable 
to  decay  as  the  hitter,  experience  haa  shown  that  they  have 
serious  disadvantages.  This  is  especially  the  case  if  a  building 
takes  fire,  when  the  expansion  that  occurs,  and  the  tendency 
to  warp  and  buckle  up,  are  often  the  cause  of  overturning  the 


WOODEN  FLOORS. 


207 


Fia.  399. — Joists  resting  on  Upper  Flange  of 
Iron  Girder. 


walls  and  prove  destructive  both  to  life  and  property.  A  heavy 
wooden  beam  will  often  burn  only  until  the  whole  of  the  outer 
surface  is  charred,  and  it  does  not  expand  materially  with  heat. 
Wooden  beams  are  there- 
fore to  be  recommended  in 
preference  to  iron  ones  un- 
less the  latter  are  encased  in 
some  fire-resisting  material. 
When  iron  girders  are 
used  to  support  wooden 
joists,  the  joists  may  rest  on 
the  upper  flange  of  the 
girder,  as  shown  in  Fig. 
399  ;  or  on  pieces  of  timber 
resting  on  the  bottom  flange 
of  the  girder,  and  bolted 
through  its  web  (Fig.  400)  ; 
or  again,  if  the  joists  are 

deep  enough,  they  may  themselves  rest  on  the  lower  flanges 
of  the  iron  girder  itself.  The  unsightly  appearance  of  iron 
girders  when  constructed  as  in  Fig.  399  may  be  entirely  avoided 

by   encasing  them   in 
wood  or  plaster. 

Stone  Templates. 
— ^The  ends  of  all 
beams  used  in  floor 
and  roof  construction 
should  either  rest  on 
stone  templates  (pad- 
stones)  or  should  fit 
into  cast  iron  beam 
boxes  which  are  built 
into  the  wall.  The 
I'eason  for  this  is  to 
allow  a  firm  seating  for  the  beam,  and  to  distribute  the  weight 
carried  over  a  large  surface  of  the  wall.  Stone  templates  are 
blocks  of  hard  stone,  from  2'  to  3'  long,  9"  to  12"  wide,  and 
4"  to  6"  thick.  The  openings,  or  pockets,  into  which  the 
beams  requiring  stone  templates  rest,  should  be  at  least  Ij" 
wider  than  the  breadth  of  the  beam,  to  allow  for  an  air-space 
on  each  side  of  it.     An  air-space,  which  may  be  c\o§»e^\y^  ^ 


Flo.  400. — Joists  carried  by  Iron  Girder. 


208       A  MANtfAL  OP  OABPRUTRY  AND  JOINERY. 

bnck  (iich  (dg  401)  oi  b)  a,  stone  hnt«l  should  bIbo  be  pm- 

1  idcd  on  the  trip  of  the  beam 

(.aat  iKin  T«a.m  Iwxes  made  laige  eniiif,li  to  allow  of  a 

liition  of  jiir  arouud  the  end  of  the  b«a,m  are  made  with  sidec 

fiom  rto  IJ"  thick,  and 

often  have  s.  longer  base 

{)Ut(   to  obtain  a  long< 

beaiing    surface    on    tt 

■^^^ll 

Encasing  of  OirderB.- 
Pliin  wooden  piiBiliga 
formed  out  of  j'  tongusd, 
grooved  and  beaded 
match-boarding,  secured 
to  rough  "firring"  pieces 
nailed  to  ovei'j  second 
joist,  as  shown   at  A   in 

Fig.   402,   may  be  used.     Fi'anied  and  panotled  linings  are  a 

superior  alternative  means  of  encasing  girders.     This  is  shown 

at  Bin  Fig.  402.     When  the  encasing  is  effected  by  laths  and 

plaster,  the  rough  packing  pieces  (drrings)  which  are  nsjuired 

to  carry  the  plasterers'  Jatlia 

are  nailed  against  every  joi^t. 
Fire-iesisting  Floors.— A 

very    elTective     fire-resiating 

Aoor  constructed  of  wood  is 

made    hy    spiking   together 

battens    or   deals   placad   on 

edge,   so    as   to   get   a   solid 

wooden    slab    of    thickness 

equal  to  the  depth    of  th« 

deals    used.       The    floor    is 

improved   by   "  grouting "    the   joists   with   liquid   plaster  of 

Paris.     Tlie  upper  surtaca  may  consist  of  the  upper  edges  of 

the  deals  planed  smooth,  or  a  layer  of  floor  boardd  niay  be  laid 

on  the  top. 

A  fire-resisting  floor  may  also  be  constructed  with  iron  or 

Btee!  girders,  on  which  rest   smaller  steel   joists   placed  from 

18"  to  ff  apart.     The  «])ace  between  those  joists  is  filled  with 

cement  concTsta  to  a  depth  of  C"  to  8'',  u  temporary  sheeting  of 
planks  heiag  liied  un  the  uaderside  to  support  the  cunci'ute 


WOODEN  FLOORS.  209 

until  it  seta.  Other  methods  of  constructing  fire-resiating 
floors  are  by  building  btlok  urchM  which  spring  from  heavy 
iron  girders,  or  by  a  combination  of  iron  girders  and  specially 
constructed  fire-clay  blocks,  supported  by  the  girders. 


Fio.  408.— Sketch  of  pirt  ot 


When  a,  wooden  floor  is  required  on  the  upper  surface  of  any 
of  the  ahove  floors,  wooden  joists  about  3"  by  3"  are  laid  on  the 
lop  of  the  fire-resisting  material,  or  if  this  is  of  concrete,  are 
partly  embedded  into  it  (Fig.  404)  when  the  concrete  ia  being 


laid.     The  joists  ai'C  often  cut  obliquely  as  shown  in  Fig.  404. 
The  floor  boards  are  nailed  to  the  joists  in  the  usual  manner. 

Instead  of  using  joists  and  boards  on  the  upper  surface  of  a 
concrete  floor,  wooden  blocks  of  shape  shown  in  Fig.  405  may  be 
used.  The  blocks  are  from  6"  to  12"  long,  3' wide,  and  from  Ij" 
to  2"  thick.    They  are  secured  together  and  in  positioii  \yyte\-n% 


210       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


first  dipped  in  a  hot  composition,  of  whicli  pitch  or  tar  forms 
the  basis.  A  decided  advantage  may  be  claimed  for  a 
block  floor,  in  that,  in  schools,  libraries,  and  where  the  floor 
cannot  well  be  carpeted,  it  is  noiseless  as  compared  with  the 
joist  and  boarded  floors. 

Dimensions  of  Floor  Boaxds.— Floor  boarding,  like  all 
timber,  however  well  seasoned,  is  liable  to  shrinl^age.  To 
minimise  this  as  much  as  possible,  floor  boards  are  cut  into 
narrow  widths,  and  in  the  best  class  of  floors  they  are  seldom 


r.—  € > 


v....  6'-'-i 


Square,  ed^fedi . 

Pig.  406. 


Fio.  407. 


If-    7' 


V—7'-.* 


Ymrfrrmm<K^mMim. 


rebated 

Pig.  408. 


irof 


relHitecL  seifUeted^ 

Fio.  409. 


'^^/^^miifmmm-k 


OrOOVG<t  ^filietoct/  ^pecuUly  TonguetLA-^rocved, 

Fig.  410.  Fig.  411. 

Floor  Board  Joints. 

more  than  4"  to  h"  wide.  Ordinarily,  however,  they  vary  from 
4"  to  7"  in  width,  and  from  J"  to  1^"  in  thickness.  It  is  not 
uncommon  in  warehouses,  or  where  heavy  traffic  exists,  to  use 
wrought  battens  or  deals,  the  thickness  of  which  is  2^"  and  3". 

Floors  are  frequently  laid  with  two  thicknesses  of  boards,  the 
lower  one  consisting  of  rough  boards  about  |"  thick.  The  top 
layer  may  be  conveniently  left  until  the  plastering  is  finished 
and  the  building  fairly  dry,  there  is  then  less  liability  of  the 
finished  floor  surface  being  aff'ected  by  dampness. 

Floor  Board  Joints.— The  edges  of  floor  boards,  or  floor 
battens,  as  they  are  also  called,  are  prepared  in  many  different 
ways.  The  joints  most  commonly  used  are  the  square-edged 
(Fig.  406)  and  the  tongued  aiid  grooved  (Fig.  407).     Figs.  408  to 


WOODEN  FLOORS. 


211 


Fig.  412. 


411  show  other  less-frequently  employed  joints  with  their 
distinctive  names  appended.  Fig.  411  shows  a  form  of  joint 
used  in  the  construction  of  superior  floors.  "With  such  a  joint 
each  board  must  be  nailed  and  laid  separately  to  the  joists,  the 
object  being  to  obtain  a  finished  floor 
surface  free  from  unsightly  nail-holes. 

Heading    Joints. — Heading    joints    are 
those  formed  by  joining  the  ends  of  boards 
together.    A  heading  joint  must  always  be 
over  a  joist.     The  ends  of  the  boards  may 
be    cut  square — a  square  heading   joint — 
(Fig.  393)  ;  cut  obliquely  through  the  thick- 
ness as  shown  in  !Fig.  385  (a  splayed  headiiig  joint) ;  or  a  tongued 
aiid grooved  joint  may  be  made  (Fig.  412).     Another  joint,  named 
9.  f(yrked  heading  joint,  and  illustrated  in  Fig.  413,  is  sometimes 
used.     For  ordinary  work,  the  lalx)ur  involved  in  the  making  of 

this  last-named  joint  is  not  com- 
pensated for  by  any  advantage 
in  its  use  over  those  previously 
described. 

Materials  used,  and  Methods 
of  Lasring  Floors.  —  Several 
different  kinds  of  timber  are 
used  for  floor  construction. 
Perhaps  that  in  most  general 
use,  and  applicable  either  to 
beams  or  girders,  floor  joists, 
ceiling  joists,  and  floor  boards  is 
red  or  yellow  deal  {Pinus  sylvestris). 
It  is  one  of  the  strongest  of  soft  woods.  Spruce  or  wMte 
deal  {Picea  exceUa)  is  also  largely  used  for  joists  and  floor 
boards.  Pitdi  pine  is  very  suitable  for  the  girders  and  binders. 
Pitch  pine,  birch,  maple,  and  oak  are  often  used  for  floor  boards. 
The  nails  used  for  nailing  down  the  floor  boards  are  named 
brads.  They  have,  as  Fig.  321  shows,  a  small  head,  which  when 
driven  below  the  surface  of  the  board  leaves  only  a  small  hole 
vrisible  on  the  floor  surface. 

The  heavy  timbers  such  as  the  girders  and  binders,  as  well  as 
the  floor  joists,  are  placed  in  position  as  the  building  proceeds. 
When  wall  plates  are  used  these  are  laid  level  at  the  proper 
height ;  the  necessary  joints  are  made  for  the  toixmmi^  iot 


Roorboard 


Fio.  413. 


212       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

^  hearths,  staircase  wells,  and  any  other  openings  that  may 
requJi'e  to  be  provided  for;  and  then  the  joists  are  placed  in 
position  as  required.  These  timbers  serve  as  a  tie  for  the  walls  ; 
they  are  also  an  aid  to  the  builder  in  carrying  up  the  higher 
parts  of  the  building,  as  they  to  some  extent  take  the  place  of 
scaffolding. 

For  ordinary  dwelling  houses  it  is  usual  to  lay  the  floor  boards 
directly  the  building  is  covered  in.  There  are  disadvantages  in 
this  plan,  inasmuch  as,  if  the  boards  are  well  seasoned,  the  damp 
state  of  the  building,  along  with  the  dampness  caused  by  the 
plastering  of  the  walls  and  ceilings,  causes  the  floor  boards  to 
swell,  and  often  to  rise  from  the  joists.  When  the  building 
becomes  dry  the  boards  again  shrink  and  open  joints  result. 
The  narrower  the  boards  the  less  the  shrinkage  that  takes  place 
in  each  one.  Again,  as  previously  explained,  wood  shrinks 
more  tangentially  than  radially  to  the  annual  rings,  therefore  a 
material  difference  will  result  from  the  way  the  boards  are  cut 
from  the  log. 

When  two  thicknesses  of  boards  are  used,  the  lower  layer  can 
be  laid  and  used  as  the  floor,  and  the  upper  layer  need  not  be 
laid  until  the  building  is  dry  and  the  plasterers'  work  is  finished. 
With  this  class  of  floor  the  square-edged  joints  are  generally 
used.  With  floors  laid  with  only  one  thickness  of  boards,  the 
tongued  and  grooved  joint  is  to  be  preferred.  The  heading 
joints  of  a  floor  are  usually  very  numerous.  They  should  always 
be  on  a  joist,  and  should  not  all  meet  on  the  same  joist ;  nor 
should  they  be  in  straight  lines. 

Floor  cramps  are  used  for  cramping  the  joints  of  floor  boards 
together  when  being  laid  in  position.  Many  different  types  are 
obtainable,  especially  for  use  with  single  layers  of  boards. 
Figs.  221  and  224  are  types  which  clip  the  joist  when  being  used. 
For  the  upper  layer  of  a  double-boarded  floor,  iron  dogs  are 
often  driven  over  the  middle  of  joists  into  the  floor  previously 
laid  ;  and  the  floor  boards  are  forced  into  position  by  folding 
wedges  of  hard  wood  bearing  against  the  edges  and  the  dogs. 

Another  plan  is  to  "  buckle  "  the  floor  boards  into  position. 
This  may  be  done  by  securely  nailing  the  outermost  of  five 
or  six  boards,  and  then  "folding"  or  "buckling"  the  inter- 
mediate boards  into  the  space  left  for  them. 


SUMMARY.  213 


Summary. 

Wooden  floors  are  known  as  singlet  dovJble,  or  framed,  according  to 
the  arrangement  of  the  timbers  composing  them.  They  consist  of 
joists,  biiiders,  girders,  floor  boards,  and  ceiling  joists. 

In  floor  joists  the  usual  ratio  of  depth  to  breadth  is  3  to  1. 

Joists  ought,  whenever  possible,  to  rest  upon  offsets  or  corbels  in 
preference  to  being  built  into  the  wall.  When  a  joist,  binder,  or 
girder  is  built  into  a  wall,  an  air-space  should  be  left  around  it 
to  prevent  decay  of  the  timber.  All  binders  and  girders  should 
rest  on  stone  templates.  Around  staircase  openings  and  fireplaces 
the  joists  are  trimmed ;  the  best  joint  for  trimming  is  the  ttLsk  tenon 
joint. 

Floors  are  strengthened  by  herring-bone  bridging,  or  by  solid 
strvUing.  Joists  and  binders  are  connected  by  a  cogged  joint. 
Binders  and  girders  may  be  connected  either  by  a  tti^k  teiwn  joint,  or 
by  means  of  an  iron  stirrup. 

Iron  and  steel  g^irders  are  much  used  in  floor  construction.  The 
heavy  beams  of  large  floors  are  often  supported  in  addition  by 
intermediate  cast  iron  columns.  Floor  boards  may  have  their  edges 
square,  tongited  and  grooved,  grooved  and  filleted,  rebated,  rebated  and 
filleted,  or  Umgvjed  and  grooved  for  secret  nailing.  It  is  often  an 
advantage  to  have  two  thicknesses  of  boards  on  the  same  floor. 

Small  rectangular  wooden  blocks,  laid  upon  concrete,  are  often  used 
instead  of  joists  and  boards. 

The  timber  used  for  floor  boards  may  be  red  deal,  white  deal,  pitch 
piiie,  oak,  birch,  or  maple.  For  joists  generally,  red  or  white  deal, 
and  for  heavy  girders,  binders,  etc.,  red  deal  or  pitch  pine  is 
employed.  Specially  devised  cramps  are  used  in  the  laying  of  floor 
boards. 


Questions  on  Chapter  VIII. 

1.  Define  the  difference  between  a  single,  a  double,  and  a  framed 
floor.     In  what  circumstances  should  each  kind  be  used  ? 

2.  How  far  apart  should  floor  joists  be  placed  ?  What  should  be 
the  sizes  of  floor  joists  for  a  single  floor  of  8  ft.,  12  ft.,  and  14  ft. 
span  respectively  ? 

3.  Draw,  to  a  scale  of  1^  in.  to  one  foot,  vertical  cross-sections 
through  the  wall  supporting  the  joists  of  a  wooden  floor,  showing 
three  different  methods  of  carrying  the  ends  of  the  joists  other  than 
by  building  them  into  the  wall. 


214      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

4.  Shew  the  method  of  "trimming"  round  a  fireplace,  and  make 
a  dimensioned  sketch  of  any  joints  you  would  use.  Give  sketches 
illustrating  herring-bone  and  solid  strutting.  (C.  and  G.  Ord., 
1900.) 

5.  Draw  a  plan  and  a  section  showing  how  you  would  trim  round 
a  fireplace.     (C.  and  G.  Ord. ,  1902. ) 

6.  Show  by  sketches  three  different  methods  of  stiffening  a  floor 
by  strutting.  Explain  what  is  meant  by  sound -boarding  and 
pugging.     What  is  pugging  composed  of,  and  why  is  it  used  ? 

7.  Draw,  to  a  scale  of  1^  in.  to  one  foot,  two  sections  showing  the 
cogged  joint  between  the  floor  joist  and  the  binder  of  a  double 
floor. 

8.  Show  by  sketches,  one-quarter  full  size,  how  you  would  tenon 
a  common  joist  (9  in.  by  3  in.)  into  a  girder  (9  in.  by  6  in.),  carefully 
marking  the  relative  proportions  of  the  various"  parts.  (C.  and  G. 
Ord.,  1894.) 

9.  Draw  to  scale  of  J  inch  to  a  foot,  plan  and  section  of  a  framed 
floor  to  a  room  20  ft.  by  14  ft.,  with  fireplace  in  the  long  side,  and 
give  two  details  of  joints,  one-eighth  full  size.  (C.  and  G-  Ord., 
1895.) 

10.  A  warehouse  floor,  24  ft.  by  32  ft.,  has  an  iron  girder  across 
the  middle.  Show  to  scale  J  inch  to  a  foot,  how  you  would  construct 
the  floor  ;  and  give  detail  |  full  size  of  the  connection  of  your  work 
with  the  girder.     (C.  and  G.  Hon.,  1896.) 

11.  Show  by  sketches  one-quarter  full  size,  and  explain,  three 
methods  of  fixing  fir  joists  to  iron  girders.     (C.  and  G.  Ord.,  1895.) 

12.  Give  I  full-sizo  sections  of  different  joints  of  floor  boards, 
including  heading  joints.     (C.  and  G.  Ord.,  1896.) 

13.  Describe,  as  it  would  appear  in  a  carefully- worded  specifica- 
tion, the  flooring  you  would  recommend,  regardless  of  cost,  for  a 
ground-floor  library,  and  similarly  describe  other  cheaper  forms  of 
flooring,  including  an  ordinary  yellow  deal  floor  laid  straight  joint, 
and  explain  the  technical  terms  used  in  your  description.  (C.  and 
G.  Hon.,  1900.) 

14.  Describe  the  most  suitable  timber  for  general  use  in  floor 
construction  for  :  girders,  floor  joists,  floor  boards. 

15.  (a)  Make  a  sketch  of  a  floor  cramp,  and  describe  the  method 
of  usi^g  it.  (/>)  Make  a  sketch  of  a  floor  brad,  (c)  Describe  and 
sketch  the  appliances  suitable  for  use  in  cramping  the  upper  layer 
of  boards  in  a  floor  having  two  thicknesses  of  floor  boards. 


CHAPTER  IX. 

WOODEN  BOOFS. 

Slope  of  Boof. — ^The  arrangement  of  the  timbers  used  in  the 
construction  of  the  roof  of  a  building  varies  according  to  cir- 
cumstances. Many  considerations,  such  as  the  class  of  building, 
the  style  of  architecture,  the  size  of  rooms,  the  material  to  be 
used  for  covering,  the  climatic  conditions,  etc.,  must  be  taken 
into  account.  Slates  and  tiles  are  most  frequently  used  as 
coverings  in  this  country,  but  other  materials — such  as  thatch, 
corrugated  iron,  asphalted  felt,  copper,  zinc,  lead,  and  concrete 
— are  often  used. 

With  copper,  zinc,  lead,  etc.,  the  roof  surface  may  be  laid 
nearly  horizontal,  but  slates  and  tiles  require  a  sloping  roof,  the 
inclination  of  which  varies  from  twenty-five  degrees  (26^*)  to 
sixty-five  degrees  (65°)  for  slates  ;  and  from  thirty-five  degrees 
(35")  to  sixty -five  degrees  (65°)  for  tiles.  A  common  pitch,  when 
slates  are  used,  is  one-fourth  (J)  or  one-third  (J)  the  span,  which 
means  that  the  vertical  distance  from  the  level  of  the  top  of  the 
walls  to  the  highest  point  of  the  roof,  when  it  slopes  equally 
both  ways,  is  respectively  one-quarter  or  one-third  the  width  of 
the  building. 

Paxts  of  a  Boof. — The  highest  part  of  a  roof  sloping  both 
ways  is  named  the  ridge ;  the  horizontal  piece  of  timber  form- 
ing the  ridge  is  called  the  ridge  piece  or  ridge  tree.  The  timbers 
placed  in  the  direction  of  the  slope  of  the  roof  are  named  spars 
or  common  rafters.  The  common  rafters,  which  are  from  3" 
to  4^"  deep,  and  2"  to  3"  thick,  should,  even  with  the  larger  size, 
be  supported  at  intervals  of  not  more  than  8'.  The  lower  edges 
of  a  sloping  roof  are  called  the  eaves.  Wall-plates,  to  which  the 
lower  ends  of  the  common  rafters  are  nailed,  8ho\i\d\i^'\i^^^<i^^ 


216      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


on  the  wall  nt  the 
which  support  the 


.  Intermediate  horizontal  timbem, 
1  rafters,  are  known  as  pniilns.  In 
dwelling  houses  the  walla 
serve  to  carry  the  purlins, 
but  with  large  buildings, 
^  Itatnad  tnuaea  are  required 
for  this  purpose.  Distinc- 
tive names  are  given  to  the 
different  types  of  roof  truss 
according  to  their  size  and 
shape.  A  Up  is  an  angle 
niadewhenabuilding,instead 

^"'l.^''';~«^'"'*"^^  v';?'''*t^*''''^.'PP*^     of   having  a  gable  as  at   J 
Roof,  Hip  Bnd  Valley  Rsftert,  otc.  6        6  ,~  ^ 

(Fig.  414)  has  the  roof 
returned  I'ound  the  end  of  the  baildiag  as  at  B.  A.nlixy  ta 
formed  when  two  roof  surfaces  meet  together  and  form  an 
internal  angle.  Hips  and  valleys  are  constructed  with  strong 
timbers  placed  on  edge  ; 
they  are  carried  by  the 
walls  or  roof  trusses. 
The  timbers  aie  named 
hip  or  valley  rafters, 
and  carry  the  common 
rafters  that  abut  . 
against  them.  Such 
short  common  rafters  ; 
are     known     as    Jaok 

Lean-to  Koof.— The 

simplest  kind  of  slop-    | 

ing  roof  is  that  where 

one  wall  is  carried  up 

sufficiently  higher  than 

the  other  to  give  the 

required  slope   to   the 

roof.     Such   a   roof   is 

called  a  lean-to  roof  (Fig.  415).     In  all  cases  where  the  length 

of  the  common  rafter  is  more  than   eight  feet,  one  or  more 

purlins  should  be  inserted. 

Oonple  Boof. — A  couple  roof  is  one  in  which  the  common 
ratters  slope  upwards  from  opposite  walls  and  meet  a  ridge 


Lean-tu  reof. 


WOODEN  ROOFS. 


217 


piece  in  the  middle.  The  common  rafters  are  securely  nailed  to 
the  ridge  piece  and  to  the  wall-plate  on  each  wall.  The  common 
rafters  have  no  tie  or  other  support  in  this  class  of  roof,  there- 
fore the  tendency  is  for  the  walls  to  be  thrown  over  by  the 


jUdgeplece 


Couple  rooF. 

Fio.  416. 


Purlin/ 


Fig.  417.— Wooden  Purlin  support* 
ing  Common  Rafter. 


weight  of  the  roof.     Such  couple  roofs  are  only  used  on  small 
buildings,  where  the  span  is  not  more  than  12'  (Fig.  416). 

How  Common  Baiters  axe  Fixed. — In  cottages  and  dwelling- 
houses  generally,  the  inside  walls  of  which  are  carried  up  to  the 
roof,  the  common  rafters  are  nailed  to  the  ridge  piece,  to  the 


/  rPurluv 

Pig.  418.  Fig.  419. 

Wooden  Purlins  supporting  Common  Rafters. 


wall-plates,  and  to  purlins  which  extend  from  wall  to  wall.  The 
size  of  the  purlins  depends  upon  the  distance  between  the  walls 
of  support ;  the  purlins  may  be  placed  either  with  one  side 
vertical  and  with  the  top  corner  cut  off  to  the  slope  of  the 
roof  (Fig.  418),  or,  as  shown  in  Fig.  417,  with  one  side  at  right 
angles  to  the  slope  of  the  roof.  When  the  purlins  are  placed 
ag  in  Fig.  417,  the  proportion  of  the  width  to  t\xe  t\i\sto^i!aa 


218      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


should  be  adjusted  so  that,  when  in  position,  a  diagonal  of  the 
cross  section  is  vertical.  When  the  slope  of  the  roof  is  steep, 
the  common  rafters  are  often  notched  on  to  the  upper  edge  of 

the  purlin  for  about  three-quarters  of 
an  inch  (Fig.  419). 

When  the  walls  which  support  the 
purlins  are  more  than  about  16'  apart, 
and  it  is  not  desirable  to  insert  a 
framed  truss  of  the  usual  type,  the 
purlins  may  be  trussed  as  explained 
in  Chap.  VII.,  and  illustrated  in  Figs. 
268  to  273 ;  or  rolled  steel  or  wrought- 
iron  girders  may  be  used  as  purlins. 
These  iron  purlins,  however,  require 
"lining  up"  with  pieces  of  timber, 
which  are  bolted  on  the  top  of  the  upper 
flange,  and  to  which  the  common  rafters  are  nailed  (Fig.  420). 

Ceiling. — The  ceiling  under  the  roof  of  a  dwelling-house  is 
obtained  by  fixing  the  ceiling  joists,  which  are  to  carry  the 
laths  and  plaster,  level  with  the  top  of  the  side  walls ;  or,  to 


i  Boiled  Girder 

Pio.  420.— Iron  Girder  sup- 
porting Common  Rafter. 


'^ydgepLe.ce 


SECTWN  through  the  RoOF  oF a  COTTAGE 


Fio.  421. 


obtain  additional  height  in  the  rooms,  the  ceiling  joists  may  be 
placed  part  of  the  way  up  the  slope  of  the  roof.  When  securely 
nailed  together  and  to  the  common  rafters,  these  ceiling  joists 
form  a  tie  which  strengthens  the  roof.  To  stiffen  them  further 
they  are  secured  together  and  to  the  purlins  with  pieces  of 
quartering,  named  stays,  about  3"  by  1^"  in  section  (Fig.  421). 


WOODEN  ROOFS. 


219 


Collar-beam    Eoof.— For   spans   between    12'  and   18'  the 
colla]>beam  roof  is  used  extensively.'    Its  construction  is  effected 


idgepiecs 


. __  _       __        _  ^    _      __  _     _ 


-  -    IZ'totB" 


Pig.  422.  -Elevation  of  Collar-boam  Roof. 

by  framing  each  pair  of  common  rafters  into  a  light  truss,*  and 
connecting  them  by  means  of  a  horizontal  tie  named  a  collar- 


•^v 


.  >0^.- 


"^.--r 


CoUar  heairv   '"^^ 


I 


Pig.  423. — Joint  between  Collar-beam  and  Common  Rafter. 

beam.     The  height  of  the  collar-beam  is  determined  by  the 
amount  of  room  required  ;  the  lower  it  is  placed,  the  stronger 


Pig.  424. — Joint  between  Collar-beam  and  Ctnuraon  Rafter. 

is  the  roof.     It  is  usually  fixed  at  one-third  or  one-half  the 
vertical  height  froDi  the  wall  to  the  ridge.    T\ie  ^om\.  cotiXv^oXAXi^ 


220       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


the  collar-beam  to  the  roof  may  be  a  dovetail-halved-joint 
(Fig.  423),  or  a  halved  and  cogged  joint  (Fig.  424).  Both  these 
joints  require  further  securing  with  bolts. 


Fig.  425.— Blrd's-mouth  Joint 
at  Foot  of  Rafter. 


Fio.  426.  —Joint  at  Head  of  Rafters  in  a 
Collar-beam  Roof. 


The  lower  ends  of  common  rafters  are  cut  and  nailed  to  the 
wall-plate  as  in  Fig.  427  ;  or,  if  the  ends  of  the  rafters  overhang 
the  wall,  they  are  cut  as  shown  in  Fig.  425.     Both  these  joints 

are  known    as    bircPs-motUh 
joints. 

Each  pair  of  common 
rafters  is  connected  at  the 
upper  end  by  means  of  a 
cleat,  leaving  a  slot  to  receive 
the  ridge  piece  (Fig.  426). 

Framed  Boof  Trasses.— 
When  the  span  exceeds  18' 
and  there  are  no  inside  cross 
walls  to  carry  the  purlins, 
framed  structures  known  as 
roof  trusses  are  used  for  the 
purpose. 
Such  ti'uases  should  be  so  constructed  that  when  complete 
they  are  as  rigid  as  possible.  With  this  end  in  view  the  timbers 
(members)  of  each  truss  are  arranged  to  form  a  series  of 
triangles.  A  guiding  principle  should  be  that  each  purlin  is 
directly  supported  by  a  member  of  the  truss  in  such  a  way  that 
the  members  are  subjected  to  direct  tension  or  compression 
stresses  onlyy  and  not  to  cross  stresses. 


Fio.  427.— Bird's-mouth  Joint  at  Foot  of 
Rafters. 


WOODEN    ROOPS. 


221 


This  principle,  along  with  the  fact  that  purlins  should  never 
be  more  than  8'  apart,  decides  the  shape  of  the  truss  for  a  given 
span.    The  joints  of  all  wooden  roof  trusses  should  be  arranged, 


A 


"Stone  ttmplcUe 

Fig.  428.— Elevation  of  a  King-poet  Roof  Truss. 


as  far  as  possible,  at  right  angles  to  the  grain  of  the  wood,  so 
that  they  will  be  least  affected  by  shrinkage. 

The  distance  between  the  trusses  is  influenced  by  the  position 
of  window   and    other  openings  ;    no    truss  should   be   fixed 
directly  over  such  an  opening.     It  is  not  economical  to  place 
trusses    much    further    apart 
than  l(y,  on  account    of   the 
increased  size  of  the  purlins 
required. 

E^ing-post  Truss.— Fig.  428 
shows  the  elevation  of  a  King- 
post truss  with  the  names  of  the 
different  members  appended. 
As  will  be  noticed,  the  truss 
derives  its  name  from  the 
central  upright,  called  the 
Eing'-poBt.  The  horizontal  tie- 
beam  prevents  the  principal 
rafters  from  spreading.  The 
struts  are  arranged  to  support 

the  principal  rafters  at  points  beneath  the  purlins.  Up  to 
spans  of  28',  with  a  pitch  of  not  more  than  one-third  the  span, 
it  is  sufficient  to  have  one  purlin  on  each  side.  In  such  a  case 
a  King- post  truss  is  most  suitable. 

Joint  at  Foot  of  Principal  Rafter. — This  joint  should  be  directly 
over  the  wall,  as  ^own  in  Fig.  429,  or  if  it  \)e  neceaaax^  Xjo  Vvj^ 


Tie  beam 


Pig.  429.— Joint  at  Foot  of  Principal 
Rafter. 


222      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

it  some  distance  from  the  wall,  as  in  Fig.  430,  a  stronger  tie 
beam  will  be  required,  since  additional  stress  is  in  such  a  case 
put  on  that  member.  Figs.  431 ,  432,  and  433  show  three  diflferent 
ways  of  making   this   connection   between   the   tie-beam  and 


Ti&  ificcm/ 


Fio.  430.— Incorrect  Position  of  Joint  in  a  Roof  Truss. 

principal  rafter.  In  each  case  the  end  of  the  principal  rafter  is 
cut  at  right  angles  to  the  grain  of  the  wood  for  half  its  width. 
In  Fig.  431  a  stump  tenon  is  cut  on  the  end  of  the  principal 
rafter,  and  a   cori*esponding  mortise   made  in   the   tie-beam  ; 

in  Figs.  432  and  433  a 
bridle  joint  is  formed. 
An  iron  bolt  may  be 
used  to  secure  the  joint 
(Fig.  428),  or  wrought 
iron  straps,  arranged  in 
a  variety  of  ways,  may 
be  employed  (Figs.  433 
and  438). 

Joint  at  Head  of  King- 
post.— Fig.  433  shows 
the  elevation  of  the 
joint  between  the  upper 
ends  of  the  principal  rafters  and  the  King- post.  Each  principal 
rafter  is  stump  tenoned  into  the  King-post— which  is  made 
wider  at  each  end  to  obtain  a  square  abutment — the  joint  being 
secured  by  a  wrought  iron  strap  placed  on  each  side  and  bolted 
through  each  member  as  shown  in  the  illustration. 


Bru/lejoi/u 


Flo.  431.  Fio.  432. 

Sketches  of  Joints  at  foot  of  Principal  Rafter. 


WOODEN  ROOFS. 


223 


Joint  at  Ends  of  Strut. — The  strut  has  the  upper  end  either 
bridled  or  stump  tenoned  into  the  lower  edge  of  the  principal 
rafter,  and  the  lower  end  stump  tenoned  into  the  lower  end  of 
the  King-post,  which  is  mortised  to  receive  it,  as  shown  in 
Fig.  433. 

Joint  between  King^-post  and  Tie-beam. — The  lower  end  of  the 


idgepiece 


strap 
h'boUs 


Fio.  488.— Details  of  the  Joints  of  a  King^post  Roof  Truss. 

King-post  is  stump  tenoned  into  the  upper  edge  of  the  tie-beam 
for  a  distance  of  about  2",  and  is  secured  with  either  : 

(a)  A  stirrup  iron  and  gibs  and  cotters  ; 

(6)  A  joint  bolt ; 

(c)  A  wrought  iron  strap  and  bolts. 
In  the  construction  of  the  truss,  the  joint  between  the  King- 
post and  tie-beam  is  left  about  one  inch  slack,  and  by  using 
as  the  fastening  either  the  stirrup  iron  and  the  gibs  and  cotters, 
or  a  joint  bolt,  all  the  joints  of  the  truss  are  drawn  close,  and  a 
camber  (arching)  of  about  \'  in  10'  is  given  to  the  tie-beam  to 
prevent  it  from  sagging  when  it  is  placed  in  position  and 
loaded. 

A  Btirrup  iron  is  a  U-shaped  wrought  iron  strap,  which  em- 
braces the  tie-beam  and  the  lower  end  of  the  King-post,  and 
is  fastened  with  two  iron  clips  called  gibs,  and  itoti  N?ei^^«& 


S24      A  MANUAL  OP  CARPENTRY  AND  JOINERY. 

called  cntUTE.     The  length  of  the  etirrup  iron,  to  the  holes 

through  which  the  gibs  and  cotters  pass,  ia  about  double  the 
depth  of  the  tie  beam.  Fig.  434  shows 
a  sketch  of  this  mode  of  fastening, 
where  two  gibs  and  two  cotters  are  in 
position  ready  for  tighteoing  up.  It 
is  advisable  to  note  carefully  the 
epacea  left  for  tightening  up  the  joint. 
These  are  shown  in  Fig,  433  where  the 
lower  gib  rest*  on  the  wooden  Xing- 
poat,  and  brings  it  down  towards  the 
joint ;  the  upper  gib  bears  against  the 
iron  stirrup,  and  in  this  way  draws 
the  tie-beam  towards  the  joint ;  ao 
that  when  the  cotters  are  driven  tight 
they  may  draw  the  joint  together. 

A  Joint  bolt,  as  has  been  explained 
previously  (p.  176),  is  a  bolt  with  a 
flat  square  head,  and  a  pointed  end 
which  is  threaded  for  a  distance  of  3" 

or  4"  i  it  is  provided  with  a  flat  nut  which  is  in  this  case  let  into 

the  King-poat,     The  length  of  the  joint  bolt  is  about  twice  the 

depth   of   the    tie-beam ;    its 

diameter    is   from    §'   to   !"■ 

In  filing,  a  hole  ia  bored  for 

the  required  distance  through 

the  tie-beam  and  into  the  end 

of  the   King-poat.      The  flat 

nut  ia  let  into  the  King-poat 

in  a  line  with  the  hole  thus 

bored,  so  that  the  end  of  the 

joint  bolt  will   pass  into  the 

nut.     It  is  tightened   up  by 

turning   the   joint  bolt  with 

a  spanner.     In  Fig.  4.')9  a  |" 

joint  bolt  at  the  lower  end 

of  a  Queen-post  is  shown,  Fm  »s.'^  F'o.  IM, 

Figs.   435   and  436  show  a     Voot  of  Queen , post  showing  Wrought  Iron 

U-shaped  wrought  iron  strap, 

bent  to  clip  the  tie-beam  and  King-post,  and  held  in  poaition 

b^  bolts.     Although  often  adopted,  this  arrangement  does  not 


WOODEN  BOOPS.  9as 

«■  of  tii^lltening  up  the  joints  of  the  truss,  and  ia  therefore 
of  aeeurins   the   ioiiit  fta  eitlier  c!  the 


1  templates  aud 


^^b|ot  80  good  I 

^^R^o  previously  described. 

^^K     Tlie  ends  of  all  tie-beams  should  I'eiit  on 

^^^ave    air-apaces    around    them    an    de- 

Bcribed  for  floor  girdefs  (p.  207). 

Joint    between    Fuilln    and    Principal 

Baftei. — ^The  best  construction  is  effected 

by  resting  the  purlin  on  the  upper  edge 

»(back)  of  the  prinfipal  rafter,  with  a 
Bogged  joint  {p.  202)  and  obtaining 
Sadditional  support  by  housing  a  cleat 
into  the  principal  rafter  on  the  lower 
side  of  the  purlin.      This  arrangement  nwKiun  rumn. 

ia  shown  in  Fig.  433.  The  carrying  power  of  the  purlina  is 
increased  if  each  is  long  enough  to  pass  over  two  bays.  Another 
plan  ia  to  tusk-tenon  the  end  of  the  purlins  into  the  side  of 
the  principal  rafter— so  that  the  upper  edges  of  the  purlin  and 
ratter  are  in  the  same  plane— securing  the  joint  with  a 
_  wedge  i  or,  if  the  tenon  only  goes  into  the  mortise  for  about 


fj  through 


>^f  the   thickness  of  the  principal  rafter,  it  may  be  secured 
^th  a  joint  bolt. 

Queen-post  Trass.— A  Queen-post  truss  is  arranged  to 
suppoit  a  roof  which  has  lino  purlins  on  each  side  of  the  ridge. 
Spans  of  ordiuaiy  pitch,  of  not  more  than  40',  allow  of  this 
IS  being  used.  A  Queen-post  truss  is  shown  in  elevation  in 
r  Fig.  438,  with  the  names  of  the  different  members  indicated. 
f  This  truss  difl'ers  fioui  a  Kingpost  truss  in  having  two  vertical 
mbers   (Qown-poita)   the   upper   ends  of   whkb  »eb  '^\&£e&. 


226       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


between  the  upper  ends  of  the  principal  rafters  and  the  ends  of 
a  horizontal  collar  or  straining  beam.  Another  member,  which 
is  not  found  in  the  King-post  truss,  is  the  straining:  rfn.     It 

lests  upon  the  tie-beam, 
between  the  Queen^posts, 
and  counteracts  the  thrust 
of  the  struts. 

The  joints  of  this  truss 
are  made  similar  to  those 
described  for  the  King-post 
truss,  with  the  exception  of 
the  Joint  at  the  bead  of  the 
Queen-post.  This  joint  is 
shown  in  elevation  in  Fig. 
439,  where  the  ends  of  the 
principal  rafter  and  the 
collar  beam  are  stump- 
tenoned  into  the  Queen-post, 
and  secured  with  wrought- 
iron  straps  and  bolts.  The 
Queen-post,  like  the  King- 
post, is  wider  at  each  end 
to  provide  a  better  abut- 
ment for  the  principal  rafter 
and  the  lower  end  of  the 
strut,  which  is  stump- 
tenoned  into  it  as  shown 
in   Fig.  439. 

The  joint  at  the  lower  end 
of  the  Queen-post  is  secured 
with  a  joint  bolt,  and  the 
straining-sill  counteracts  the  thrust  caused  by  the  strut. 

Other  Wooden  Roof  Trusses.— The  King-  and  Queen-post 
roof  trusses  just  described  are  typical  examples  of  truss  con- 
struction for  roofs  of  ordinary  pitch.  An  almost  endless 
number  of  modifications  is  however  to  be  found,  even  in 
trusses  built  of  wood  only  ;  while  with  a  combination  of  wood 
and  iron  still  further  scope  for  modification  is  available.  Figs. 
440  to  442  illustrate  some  of  the  chief  variations  from  the  types 
already  explained.  Figs.  440  and  441  show  in  elevation  trusses 
having  three  purlins  on  each  side  and  therefore  suitable  for 


Section 

through  h& 

Fia.  439. — Details  of  Joints  at  Upper  and 
Lower  Ends  of  Queen-post. 


WOODEN  ROOFS. 


227 


spans  to  about  52'.  In  Fig.  441  the  Queen-posts  are  so  placed  as 
to  support  the  middle  purlin  on  each  aide,  and  a  King-post  is 
added  with  struts  in  order  to  support  the  ridge  and  upper  pur- 
lins. In  Fig.  440  smaller  posts  are  added  on  either  side  of  the 
Queen-posts ;  these  are  called  Frincess-postB,  and  provide  the 


FlO.  440. 


Fio.  441. 
Boof  Trusses  for  Span  up  to  50  foot. 


abutment  for  the  lower  ends  of  the  short  struts  that  support 
the  lower  purlins. 

Fig.  442  is  a  diagram  of  a  still  larger  truss,  one  which  supports 
four  purlins  on  each  side.  With  such  a  truss  there  are  often 
two  principal  rafters — one  extending  to  the  Queen -post  only 
(called  a  cusMon  rafter)  ;  the  other,  which  rests  on  the  top 
of  this,  and  extends  to  the  ridge,  being  bolted  at  intervals  to 
the  lower  one.  It  might  be  difficult,  in  a  truss  of  this  size,  to 
obtain  a  tie-beam  long  enough  in  one  piece.  A  tie-beam  in 
two  lengths  should    have   the    lengthening   ^om\i   (o^Vv^tk.  Sa 


228       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

generally  a  scarfed  joint)  bet^veen  the  Queen-posts,  with  the 
straining  sill  to  act  as  a  fish-plate  or  cleat. 


Fio.  442. — Line  Diagram  of  a  Roof  Truss  with  four  Purlins  on  each  side. 

Such  large  trusses  require  very  heavy  timbers  in  their  con- 
struction ;  and  as  the  roofs  they  support  have  a  wide  surface, 
the  wind  has,  in  stormy  weather,  a  considerable  effect  upon 


Fio.  443. — Elevation  of  a  Roof  in  two  Bays. 

them — a  fact  which  must  be  taken  into  account  in  their  con- 
struction. In  large  sheds  or  buildings  of  wide  span  where  it  is 
no  inconvenience  to  place  pillars  of  cast  iron,  the  roof  may  with 


Fio.  444.— Line  Diagram  of  a  Shed- Roof. 

advantage  be  constructed  in  bays.  Fig.  443  shows  a  roof  of 
this  desci'iption  having  two  bays.  The  same  principle  may  be 
applied  to  any  larger  building  and  any  number  of  bays. 
Fig.  444  sho^vs  in  line  diagram  a  cross  section  of  a  shed-roof 
where  the  light  of  the  room  is  entirely  obtained  from  the  roof. 


WOOPKN  BOOFS.  229 

In  this  example  the  side  of  the  I'unf  containing  the  lights — 
preferaWy  faiung  the  north— is  of  greater  inclination  than  the 
ODe  covered  with  slates. 

Combined  Wood  and  Iron  Trusses.  —Roof  ti-naaea  are  often 

conatructed  with   a  cimiliination  of   wood  and  iron.     In  Buch 

,  trussies  the  members  in  temion  are  of  iron  ;  those  in  compressiim 

e  of  wood.     Iron  memberB  in  roof  tniBaes  impart  an  appear- 

Lce  of  lightness  without  sacrifice  of  strength,  and  when  used 

with   iron    connectionB    also    make    it    practicable   to   employ 

simpler  joints.     The  main  objection  to  this  class  of  truss  is 

that  while  the  iion  is  affected  by  varying  temperatnrea  and 

expands  with  heat,  the  wood  is  practically  not  affected.    This 


v.  J.  plate 


B'di^rence  of  liehaviour  renders  the  truss  liable  to  be  over- 

strained  in  parts.     Again,  plaster  ceilings  cannot  conveniently 

B  secured  when   an   iron  tie-rod  takes   the  place   of  the  tie- 

A  truBB  s\iita,ble  for  a  roof  having  one  purlin  on  each  side 

is  ahowii  in  Fig.  445.     In  this  truss  an  iron  Klng-Solt  takes  the 

I  place  of  the  wooden  King-post.     The  lower  ends  of  the  principal 

trafteiB  fit  into  cast-iron  shoes  which  are  secuied  to  the  tie-beam 

txrtth  bolts  and  coach  screws. 

Fig.  446  shows  a  modified  form  of  coUai'-beani  truss  with 
B>tension  rods  instead  of  the  tie-beam,  and  with  a  king-rod 
r  replacing  the  king-post.  In  this  example  the  collar-beam  is 
placed  so  that  it  directly  supports  the  lower  purlin,  and  the 
truss  aupports  two  purlins  on  each  side.  By  placing  the  collar- 
beam  higher,  and  dispensing  with  the  strut,  this  type  of  truss 
could  be  uaed  instead  of  a  Kiiig-poBt  truffl.     , 


230       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

Fig.  447  shows  part  elevation  of  a  modified  Queen-post  truss, 
the  only  alteration  being  in  the  substitution  of  bolts  for  the 


PiLrUn/ 


Fio.  446. — Elevation  of  a  Roof  Truss  with  Iron  King-rod  and  Wrought- 

iron  Tie-rods. 

Queen-posts,  with  a  consequent  simplifying  of  the  joints. 
Trusses  for  larger  spans  are  shown  in  Figs.  448  to  450.  Fig.  451 
shows  an  ornamental  cast-iron  strut  for  a  roof  truss,  the  only 
wooden  members  of  which  are  the  principal  rafters. 


Qiieenradf 


Stretinirta  Sill 


Tie  beanv  \ 

— ^ 


nut0y 

3 


Fig.  447.— Part  Elevation  of  a  Roof  Truss  with  Iron  Queen-rods. 


Cast-iron  connections  are  often  used  in  order  to  simplify  the 
joints  of  both  wooden  and  combination  trusses.  Figs.  452  and 
45.3  show  in  detail  two  different  connections  at  the  foot  of  the 
principal  rafter.  Fig.  454  is  a  sketch  of  the  cast-iron  head 
used  at  the  upper  end  of  the  principal  rafters  in  Fig.  446. 
When  long  wrought-iron  bolts  are  used  as  in  Figs.  449  and  450, 
they  are  best  if  both  ends  are  threaded  and  provided  with  nuts 
which  should  bind  against  large  plate  wdshers  when  tightened. 


WOODEN  EOOFS. 


Typea  oi  CompoaiW  Roof  TruiBea, 


232       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

Ceiling  Joists. — When  wooden  roof  truHsea  are  used,  and 
a  horizonta,!  plaster  veiling  is  required,  the  ceiling  joists  may  ; 

(a)  be  notched  and 
nailed  to  the  under  aides 
of  the   tie-beams  ; 

(6)  rent  on  wooden  flUets 
nailed  to  the  sides  of  the 
tie-beams  so  as  to  come 
either  level  with  the  under 
side   or  part   way  up   the 


(c)   rest   on   the   top   of 
Wrought-     jfjg     tie-beams     and     be 

nailed  down  to  them. 
tinveniently  fixed  to  ii'on  tie-rods, 
finish  at  the  eaves  depends    upon 


Ceiling  joiats  cannot  be 

Eaves   of  Soof.  -Thi 
whether : 

(a)  the  roof  finishes  practically 
surface  of  the  wall ; 


»  line  with  the  vertical 


FlO   152. 
AltarnntlTQ  Airongemonl 


icipal   Itafter. 


(b)  the  roof  o^eihanga  the  wall  for  some  diKtance  ; 

(k)  the  wall  is  coi  tmued  above  the  eavea,  with  the  rain-water 
gutter  in  the  angle  between  the  wall  and  the  roof  sui'face. 

Where  the  roof  finishes  flush  with  the  surface  of  the  wall, 
as  in  Fig.  433,  the  lower  endrt  of  the  common  rafters  are  cut 
io  £t  the  wnU-pkte,  and  the  M.vm  pifitBT  lies  partly  on  the 


WOODEN  B00F8. 

■wall,  Ijeiiij;  secured  to  the  wall-plate  ;  or,  it 
j(iCtijiji  lii'ick,  or  atime,  corbeh  plaL'ed  froia  1 

Overhanging  Eaves,  — Fi;;, 
428,  A,  abows  the  eiivea 
overhaiigiiig  the  wall  ; 
tliJK  method  affoi'dii  a 
means  of  protecting  the 
wall  from  the  weather. 
The  projeetioD  variea  uon- 
eiderably,  and  may  be 
anything  Uinu  4"  to  2'. 
The  lower  ends  of  the 
common  rafters  may  be 
wrought  and  moulded, 
with  the  eaves  gutter 
can'ied  by  wrougl it-iron 
Btrapa  nailed  or  screwed  to 

every  second  or  third  rafter  :  or  a  wide  vertical  board,  named 
a  bacia  board,  may  be  nailed  to  the  ends  of  the  common  rafters. 


Cast  iron,  heeut 


it  Uppor  E 


In    Fig.    455,   whieh    ia    a    seetion    through    the    eavea,    the 
\  board  i^j&ggn  ffJHi  ii  bed  mg^c^  .^VE^  V*  ^'''  ''■''^ 


234       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


Section  fhrouah  cl 
Qxstiron  Gutter  behm 
€L  parapet  waliy. 

FlQ.  456. 


supporting  the  eaves  gutter.  The  boarding  on  the  under  side 
of  the  common  rafters — which  may  either  be  nailed  to  the 
lower  sides  as  shown,  or  fixed  horizontally,  as  indicated  by 
dotted  lines— is  named  soffit  boarding. 

Gutters  behind  Parapet  Wall. — Fig.  438  shows  on  its  right  side 
a  wall  reduced  in  thickness,  and  continued  above  the  roof  sur- 
face. Such  a  wall  is  known  as  a  parapet  wall.  In  these  cir- 
cumstances the  rain-water  gutter  is  formed  in  the  angle  behind 

the  wall.  Several  different  types  of 
gutter  are  used  ;  and  as  the  arrange- 
ment of  the  timbers  is  governed 
by  the  type  of  gutter,  it  will  be 
necessary  to  describe  it  in  detail. 

When  the  gutter  is  of  cast  iron, 
as  shown  in  section  in  Fig.  456, 
and  the  wall  is  diminished  in  the 
manner  indicated,  the  lower  ends  of 
the  common  rafters  may  rest  on  the 
wall-plate  as  shown. 

Cast-iron  gutters  are  made  in 
long  lengths,  and  have  the  advan- 
tage of  not  requiring  so  great  a  fall  as  lead  gutters.  The 
joints  are  made  with  a  cement  obtained  by  mixing  cast-iron 
borings  with  sal-ammoniac  and  water.  When  lead  is  used  for 
the  gutter  it  may  be  either  a  parallel,  box,  or  trougb  gutter, 
that  is,  of  the  same  width  throughout  its  length  ;  or,  it  may 
be  a  tapering  gutter,  i.e,  one  which  varies  in  width  according 
to  the  length  and  the  amount  of  fall. 

Parallel  gutters  are  from  9"  to  13"  wide,  and  require,  on  the 
roof  side  of  the  gutter,  a  horizontal  beam  similar  in  size  to  a 
roof  purlin,  and  called  a  pole  plate,  which  carries  the  lower 
ends  of  the  common  rafters.  The  space  between  the  pole  plate 
and  the  wall  is  prepared  for  carrying  the  lead  gutter.  As 
sheet  lead  cannot  well  be  laid  in  longer  lengths  than  10',  and 
requires  a  fall  of  at  least  one  inch  in  ten  feet,  the  boarding 
which  carries  the  lead  must  be  laid  accordingly.  Ail  gutter 
boards  nmst  be  firmly  supported,  must  have  their  length  in 
the  direction  of  the  flow,  and  must  be  free  from  all  sharp 
edges  or  arrises.  To  obtain  these  conditions  it  is  necessary 
to  have  gutter  bearers,  to  which  the  gutter  boards  are  nailed, 
placed  from  15"  to  18"  apart.     Fig.  457  is  a  vertical  cross-section 


WOODKN  HOOFS. 


] 


238       A  MANlTAL  OV  CARPENTRY  AND  JOINER*. 

of  a  pHrallel  gutter  behind  a,  parapet  wall,  and  Fig.  458  is  a 
section  of  a  Bimilar  gutter  behind  a  stone  cornice,  where  thA 
ariaiigeiiient  of  the  I'nof  timbera  is  similar  to  that  behind 
a.  pai-apet  wall. 


aiiar/Uin' 


In  F  ga  460  and  4ri  crnsi  tiect  nns  a  e  show  through  taper 
gutters  beb  n  1  a  atone  cor  ce  a  i  pa  apet  wa  1  respect  vely 
"W  th  a  taper  g  tter  the  c  o  aftc  -a  ay  be  supported, 
by  a  wall  plate  a  pcle  plate  !e  ng  d  pensed  w  th  A  taper 
fitter  s  app  cable  to  any  pla  e  wi  e  e  a  pan  llel  gi  tter  can 
bo  used     To  secure  the  aecBEaary  fall    bearers  of  gradi 


WOODEN    ROOFS. 


Ilnci'eatting  1eDj!;tb  are  nailed  to  the  sides  of  the  ci 
Such  a  gutter  is  of  neceiwity  widest  at  the  highest  point. 
8liai>e  of  the  plau  of  the  gutter  depends  on   the  slope  o 


roof  and  the  position  of  the  outlets.  The  flatter  the  roof,  the 
wider  is  the  highest  part  of  the  gutter,  as  will  be  seen  bj 
leferring  to  Figs,   4fi3,  464  itnd  466. 

A  gutter  between  two  alopliiK  roofs  that  meet  may  be  of  cast 
iwMi  tt  JB  Fig.  466,  in  which  case  flangeB  on  tVft  dxAat  s\S*» 


238       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


serve  to  carry  the  lower  ends  of  the  common  rafters.     Fig.  459 
shows  a  parallel  gutter  lined  with  lead,  where  a  pole  plate  is 

required  on  each  side 
to  carry  the  common 
rafters.  Fig.  462  is 
the  section  of  a  taper 
gutter  between  two 
sloping  roofs.  Instead 
of  the  wall  which  is 
shown  carrying  the 
common  rafters  in  Fig. 
462,  a  beam  or  trussed 
girder  might  be  used. 
Roll    and    "Drip, — The 


Section  throug/t  acast- 
iroivGuUer  betweefpZroo/s. 

Fio.  46a. 


joints  which  are-  used  for  connecting  the  sheets  of  lead  together, 
and  for  which,  in  gutters  and  lead  flats,  the  carpenter  has  to 


Gutter- 
bearers. 


*Z 


Section  through  a  leojii  drip. 

Fio.  467. 


Fio.  468. 


y-z'A 


Bottle  nose  drip 
Fio.  469. 


Section  through  a  leadrM 
Fig.  470. 

lead  tingle 
bebf(ften,the  Z  sheets 


Section  through  a  hollo  unroll 

Fio.  471. 


make  provision,  are  the  roll  and  drip.     Typical  examples  of 
these  are  shown  in  Figs.  407  to  471.     It  ought  to  be  noticed 


WOOBKN  BOOIW. 


pbut  the  upper  part  of  the  roll 
Sbf  a  little  more  tiiiin  the  width. 


cesHpool  la  a  lead  lined  wooden  box   placed  at 
the  lowest  part  (if  a  lead  gatter     Into  it  runs  the  water,  to 
be     afterwards    con- 
veyed   by    nieaoB   of      , — — ___-___-^_^,_^_  _^^   -  -, 

'o- water   pipes  "  '~' 

f.to  the  drninH.      The 
s  bott'im 
$  thecHBspool  should 

led  covering  to  pre- 
tt  dirt,  dead  leaves, 
from  entering 
id  choking  the  rdn- 
Mter   pipe.       Fig.   476   is    a   longitudinal   scL-lion    through   a 

QntterB  behind  ChinmeyE. — Gutters  behind  chimneys  are  sel- 
dom of  such  length  that  they  require  drips.     If  the  length 
~a  four  feet  it  may  be  advisable  to  p\%i:6  &  lo'^  v 


au      A  MANUAL  OF  OARPSNTRY  Aim  SQTSSKi: 

middle  and  arrange   the    gutter   boiirda    to    fall    each    waj. 
Fig.  477  is  a  ecoas-aection  through  such  a  gutter. 

Snow  BoardB,— To  prevent  the 
damniing-up  and  consequent  leak- 
age resulting  from  accumulationg. 
of  anow,  dead,  leaves,  etc,  io  the 
lead  gutters  above  described, 
niugh  frames  of  wood  are  usually 
laid  over  them.  They  also  serve 
Co  protect  the  lead. 

Oablea.— With  roofs  that  have 
overhanging  eaves,  it  ia  quite  Si 
usual  method  of  coDatruction  ti> 
arrange  the  roof  to  overhang 
the  gables,  and  to  hide  thi 
common  rafters  and  the  ends 
of  the  slates  with  sloping  boards  called  ba^e  boards,  and. 
ahown  in  Figs.  531  and  532.  (Jreat  variety  nf  style  of  hargo 
boards  exiata,  from  the  plain  board  about  7"  wide, 
simple  capping  on  the  top,  to  the  framed  structure  that 
almost  completely  hides  the  gable.  In  all  cases  care  should 
be  taken  to  have  thoroughly  seasoned  timber  entirely  free 
from  sap  wood,  to  have  well-made  joints  so  arranged  that  the 
weather  cannot  affect  them,  and  to  have  them  painted  and 
properly  secured.  The  capping  on  l«rge  boards  should  be 
wide  enough  to  overlap  the  joint  between  the  slates  and  tha 

Trimming. — When  roof-lights,  chimney  shafts,  large  venti- 
lators, etc.,  occur  on  a  roof,  the  common  rafters  around  them 
require  framing  in  order  to  suppoi't  the  ends  of  the  short) 
rafters.  The  joint  used  ia  the  mortise  and  tenon  secured 
with   wedges  or  nails,  and  the  meth(id  of  franiing  is  called 


BoofB  to  be  covered  with  Lead  dt  Zinc— Hoofs  of  this 
description  have  their  surfaces  nearly  horizontal  and  are' 
covered  with  Imarda,  care  being  taVen  to  nail  down  the  edge* 
of  the  boards  so  that  there  is  no  warping  nor  projecting 
arrises.  The  preparation  of  the  necessary  drips  and  rolls  for 
the  plunilwr  ia  the  work  of  the  carpenter,  and  he  must  know 
that  sheet  lead  ought  not  to  be  laid  in  longer  lengths  than 


10  feet,  I 


1  wider  sheets  bham  3  feet. 


WOODETf  ROOFS. 


I  The  boarded  Buriaees  are  carried  on  rafters  that  require  to  be 
ronger  than  the  ordioary  rafter  ;  if  the  span  ia  great  they  ai'e 
supported  by  girders  of  wood  or  iron. 

Such  roofs  are  often  covered  with  vulcanite  or  other  bito- 
minoua  Bubatance,  which,  wlien  there  is  no  traffic  OTer  it, 
raakea  a  good  covering  material.  A  roof  surface  covered  with 
thie  niatei'ial  requires  an  inchnation  of  about  1  in  40  ;  no  rolls 
or  di-ipB  are  needed. 

Latticed  Tmaaes. — A.  type  of  truss  niitch  used  for  temporary 

structures,  the  roofs  of   which  are  covered  with  boards  and 

roofing  felt,  is  a  lattlcsd  or  bowstrli^  truss  shown  in  elevation 

in  Fig.  478. 

'''       It  is  built  up  of  small  scantling,  and  has  a  rise  in  the  centre 

^^BEftbout  one-eighth  the  span.    It  is  applicable  to  roofs  of  any 


span,  the  size  of  the  timbers  natui'ally  increasing  with  the 
width  of  the  span.  The  tie-beam  is  composed  of  two  thiclinesgBS, 
between  which  the  braces  or  lattices  are  fixed.  The  trusses  are 
from  six  to  ten  feet  apart.  The  purlins,  which  are  much 
lighter  than  the  ordinary  roof  purlins,  are  about  two  feet  apart, 
and  rest  on  the  top  of  the  curved  ribs  ;  they  are  directly  sup- 
ported by  the  upper  ends  of  the  braces. 

The  covering  boards  are  laid  either  at  right  angles  to  or 
diagonally  with  the  piu'lins,  and,  as  the  roof  is  curved,  they 
require  bending  when  being  placed  in  position. 

This  type  of  truss  is  also  often  used  when  the  roof  cuvering  is 
of  corrugated  iron. 

It  is  necessary,  in  the  construction  of  a  number  of  aimilar 
latticed  trussee,  that  the  outline  be  set  out  on  the  floor,  and 
each  trues  put  together  according  to  the  same  outline.  The 
1,  which  are  too  Bimple  tu  need  deBchptwo,  asa  »«cas«5. 


242      A  MANUAL  OF  CARPENTRY  AND  JOINERY.     . 

by  being  well  nailed  together  in  the  smaller  trusses ;  in  lar^^r 
trusses,  bolts  may  in  addition  be  used. 

Mansard  Truss.— Fig.  479  shows  the  elevation  of  what  is 
called  a  curb  or  Mansard  roof  truss.    This  truss  is  used  with 


Pio.  479. — Elevation  of  a  Mansard  Truss. 


advantage  when  it  is  desired  to  have  an  additional  attic  or  an 
upper  room  in  a  building  without  the  expense  of  carrying  up 
the  walls  to  accommodate  the  ordinary  type  of  truss.  A 
suitable  method  for  determining  the  outlines  of  the  truss  is 

shown  in  Fig.  480.  The 
semicircle  is  divided 
into  five  equal  parts. 
The  points  1  and  4,  and 
the  centre  of  the  arc 
2 — 3,  give  the  angular 
points  of  the  outline  of 
the  truss.  Many  modi- 
fications of  this  sha})e 
are  adopted  to  suit  the 
size  of  tlie  room  re(iuired,  the  roof-covering  used,  etc. 

Gothic  Roof  Trusses, — In  public  buildings  of  importance, 
such  as  churches,  schools,  assembly  rooms,  etc.,  it  is  very  usual 
to  have  a  roof  of  high  pitch,  and  to  make  a  special  feature  of 
its  construction  and  decoration.  When  the  pitch  is  steeper 
than  forty -Gve  degrees  (45°)  the  style  tends  towards  the  Gothic 


FiQ.  480. 


WOODEN  EOOFS. 


243 


st^le  of  architecture,  with  ita  pointed  arches  and  windows,  aod 
its  distinctive  mouldings.  Trusaes  supporting  roofs  of  this 
deacription  are  styled  Gothic  roof  trussea.  The  raemhera  of 
such  trusses  are  subjected  to  niore  sti'eHs  than  are  those  of 
flatter  roofs,  as  they  present  larger  surfaces  to  be  affected  by 
high  winds. 


I.— Gothic  Roof  Truss. 


All  roof  trusses  are  stronger  when  provided  with  a  tie-beam 
or  tie-rod  at  the  eaves  level.  As  a  geneml  rule,  however,  sucli 
cross  ties  are  absent  in  (iothic  roof  trusses,  and  the  roof 
timbers  are  consequently  of  large  section.  The  general  style  is 
OD  the  lines  of  the  collar-beam  truss,  the  angular  parts  (spandrel) 
under  the  collar  being  filled  in  with  curved  ribs.  To  throw  the 
weight  na  low  as  possible  on  the  wall,  these  curved  ribs  often 
terniinato  at  from  three  to  six  feet  below  \A\«  ea-Nea  \ot^ 


244      A  MANUAL  OP  CARPENTRY  AND  JOINERY. 

The  walla  carrying  Gothic  roof  trusaeH  are  geoerally  atrength- 
ehed  by  buttresses  placed  opposite  the  position  occupied  by  the 

Fig.  481  shows  an  elsvation  of  a  little  more  than  one  half  of  a 
Gothic  roof  truss  with  the  main  dimensions  indicated.     ~^ 


curved  ribs  may  be  cut  out  of  one  thickness,  with  spliced 


joints  as  shown  in  Fig.  481  ;  or  they  may  be  built  up  of  two  or 
three  thicknesses,  with  overlapping  joints,  and  nailed,  acrewad, 
or  pegged  together.  The  joints  are  secured  with  iron  straps 
or  bolts,  or  with  bolts  passed  through  them  as  shown. 

Magnificent  examples  of  Gothic  roof  trusses  are  to  be  found 
in  many  of  the  cathedrals  of  the  country,  as  well  as  in  other 
important  buildings,  and  the  student  of  carpentry  would  do 
well  to  examine  some  of  these  in  detail 


WOODEN  ROOFS. 


245 


Hammer  Beam  Trasses. — When  a  Gothic  roof  truss  has,  at 
the  eaves  level,  a  short  horizontal  member  to  support  the 
curved  ribs  above  it,  this  member  is  called  a  hammer  beam, 
and  the  truss  is  known  as  a  hammer  beam  truss.  Fig.  482 
shows  in  elevation  a  hammer  beam  truss,  and  Figs.  483  and 
484  are  line  diagrams  of  other  types  of  a  similar  truss.  It  will 
be  noticed  that  judicious  use  is  made  of  bolts  to  support  the 
outer  ends  of  the  hammer  beams. 

The  hammer  beam  truss,  in  its  many  and  varied  forms,  lends 
itself  to  elaborate  decoration  and  ornamentation.  The  triangu- 
lar spaces  are  often  filled  with  Gothic  tracery,  while  the  ends  of 
the  hammer  beams  are  richly  carved,  often   with  allegorical 


Fio.  483.  Fio.  484. 

Line  Diagrams  of  Gothic  Roof  Trusses. 

figures.  This  is  sometimes  done  to  such  an  extent  that  the 
main  timbers  of  the  roof  are  scarcely  discernible. 

Such  roofs,  being  subject  to  considerable  wind  stress,  are 
often  braced  from  truss  to  truss  in  the  plane  of  the  roof.  An 
alternative  plan  is  to  insert  straight  or  curved  braces  from,  the 
purlins  to  the  trusses,  as  shown  on  the  right  hand  side  of 
Fig.  481. 

Pyrapinid  or  Turret  Boofs. — ^These  vary  much  in  size  ;  they 
may  have  a  triangular,  square,  polygonal,  or  circular  base,  and 
may  be  straight  or  curved  in  section ;  they  may  be  large  enough 
to  require  supporting  by  heavy  framed  and  braced  trusses, 
which  form  the  main  structure  ;  or  the  framing  together  may 
be  a  very  small  matter.  The  guiding  principles  of  roof  and 
truss  construction  generally  apply,  and  their  detailed  con- 
sideration is  only  necessary  because  they  present  good  examples 
of  the  application  of  practical  geometry  to  rooi  consXiVMcXAoxi. 


246       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

Applied  Geometry  in  Boof  Construction. — The  determina- 
tion of  the  lengths  and  end-bevels  of  roof  timbers  affords  good 
examples  of  the  application  of  geometry  to  the  carpentry  of 
roof  construction.  The  difficulties  which  may  occur  in  such 
work  will  be  obvious  from  an  examination  of  Fig.  485,  which 
illustrates  a  hipped  roof. 

A  hip  is  the  ridge  formed  when  a  roof,  instead  of  ending  at  a 
gable  as  at  A  (Fig.  414),  is  returned  round  the  end  of  a  build- 
ing as  at  B.  It  may  also  be  defined  as  the  ridge  formed  when 
two  sloping  roof  surfaces  meet  in  a  line  inclined  to  the  hori- 
zontal. A  valley  is  the  line  in  which  two  sloping  roof  surfaces 
meet  to  form  an  internal  angle. 

It  is  clear  that  the  lengths  and  end-bevels  of  the  various 
timbers  will  depend  upon  : 

(1)  the  inclination  of  the  roof  surfaces  ;     * 

(2)  the  angles  at  which  the  different  walls  of  the  building 
meet  each  other. 

In  order  to  obtain  these  lengths  and  bevels  on  scale  draw- 
ings, it  is  necessary  to  apply  the  principles  of  projection 
explained  in  Chap.  III.  In  the  following  examples,  the  lengths 
of  members  are  in  most  cases  measured  along  the  centre 
lines.  In  all  cases,  the  widest  surfaces  of  the  member  are 
referred  to  as  its  ddes^  while  the  surfaces  at  right  angles  to  the 
sides  ai"e  called  edges. 

Lengths  and  Bevels  of  Common  Rafters. — A  vertical  cross  section 
through  a  roof  with  the  walls  and  ridge-piece  in  position  shows 
at  a  glance  the  lengths  and  end-bevels  of  the  common  rafters. 
In  each  of  the  Figs.  485  to  487,  A  indicates  the  bevel, — i.e,  the 
angle  of  the  side-cut — at  the  upper  end,  and  B  the  bevel  at  the 
lower  end,  of  each  common  rafter.  It  will  be  seen  that  these 
two  angles  together  are  always  equal  to  a  right  angle,  the 
edge  of  the  common  rafter  being  the  hypotenuse  of  a  right- 
angled  triangle.  If  the  lower  ends  of  the  common  rafters 
overhang  the  wall,  then  that  end-bevel  will  be  the  same  as 
at  A,  to  enable  the  fascia  board  or  gutter  to  be  fixed  against  it. 
The  edge-cut  at  both  ends  of  the  conmion  rafters  is  "  square," 
i.e.  at  riorlit  antrles  to  the  lentjth. 

It  is  plain  that  with  ridged  roofs  all  the  common  rafters  will 

have  the  same  length  and  end-bevels  only  when  the  side  walls 

are  of  equal  height  and  parallel,  and  the  ridge  is  central  in 

position.     In  all  other  cases,  the  length  and  end-bevels  of  the 


BOOP  BEVFXS. 


.p[^r  eni  of  Hip  Baftor, 
.].^reL]|-DutIltpI<sftcr. 


.■.l.iiidB  U.  C  In  FlgB,  ^SduiA^Sl.l 


248       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


Fig.  486.— Roof  Bevels. 


Fig.  487.— Roof  Bevels. 

AB.    Length  and  Bevels  of  Comtuon  Rafters. 
MN.   Length  of  Hip  Rafter. 

C.  Bevel  for  side  cut  at  upper  end  of  Hip  or 

Valley  Rafter. 

D.  Bevel  for  side  cut  at  lower  end  of  Hip  or 

Valley  Rafter, 


rafters  will  vary ;  they 
may  easily  be  deter- 
mined by  drawing  a 
cross- section  through 
the  roof. 

The  lengtba  and 
Bevels  of  Hip  and 
Valley  Rafters.  —  To 
obtain  these,  it  is 
first  necessary  to 
draw  the  plan  of  the 
building,  with  the 
main  roof  timbers  in 
position.  If  the  in- 
clinations of  both 
sides,  and  of  the  end 
of  the  roof  are  the 
same,  and  if  the  end 
wall  is  at  right  angles 
to  the  side  walls, 
then  the  plans  of  the 
hip  rafters  bisect  the 
right  angles,  and  the 
two  hip  rafters  are  of 
the  same  length,  as 
shown  in  the  upper 
part  of  the  plan  of 
Fig.  485.  On  the 
other  hand,  if  the 
end-slope  of  the  roof 
differs  from  the  side- 
slopes,  the  plan  of  the 
hip  rafter  does  not 
bisect  the  angle. 
Again,  if  the  end  is 
not  at  right  angles  to 
the  side  walls,  then 
one  of  the  hip  rafters 
is  longer  than  the 
other,  as  shown  in 
Fig.  486. 


ROOF  BEVEIS.  249 

In  obtaining  the  lengths  of  the  hip  lufters  it  ia  always  beet 
to  work  from  the  centre  lines  of  the  upper  edges  of  the  hip 
rafters  and  ridge  piece.  The  length  of  the  hip  rafter  ie  obtained 
by  considering  its  plan  as  the  base  of  a  right-angled  triangle. 


Matbuds  ol  Supporting 


the  hypotenuse  of  which  is  the  true  length,  while  the  altitude  is 
the  height  of  the  ridge  above  the  wall  level.  Id  Figs.  486  to 
487  M^  is  in  each  case  the  length  of  the  iiip  or  valley  ratter. 

The  lower  end  of  a  hip  rafter  rests  upon  the  wall,  in  the 
Uigle.  It  may  be  supported  further  by  an  ang-le  tie  (Fig.  488), 
or  be  provided  with  an  uigle  tie  and  dtagou  ]^6M,  ■p\iuift4  wsvoea 


250       A  MANUAL  OP  CARPENTRY  AND  JOINERY. 

the  corner  ae  shown  in  Fig.  469.  The  upper  end  generally  abuU 
against  the  ridge,  and  is  supported  either  hy  a  division  wall  or 
by  a  roof  truss. 
The  angles  of  the 
side  cuts  (bevels 
for  the  enda  of 
the  hip  rafter) 
— neglecting  the 
special  abutmenb 
required  when  a 
dragon  piece  ii 
used  (Fig.  489)- 
are  together  equal 
to  a  right  angla 
This  is  shown  in 
Figs.  486, 486,487, 
and  494,  where 
the  bevel  at  the 
upper  end  is  in 
each  case  lettered 
0*  and  the  bevel 
at  the  lower  end 
1. 

FigB.  490and491 
show  how  to  olv 
tain  the  edge-cut 
at  the  upper  end 
of  the  hip  i-after. 
The  rafter  may  fit 
against  the  side 
of  the  ridge  (Fig. 
490),  or  the  ridge 
may  be  cut  to 
fot'ni  a  seating  on 
which  the  hip 
rafters  are  mitred 
M«tl«rf.«(oW»ij,ihgB^d»crfui^r™^^^  to   fit  each  other 

(Fig.  491).  In 
either  case  the  problem  resolves  itself  into  finding  the  true 
shape  of  a  right-angled  triangle,  the  plane  uf  which  is  inclined, 


WOODEN  ROOFS. 


251 


the  inclination  depending  upon  that  of  the  hip  rafter.     If  the 

hip  rafter  were  horizontal — which  is  never  the  case — the  plan 

of  the  vertical  plane  of  intei-section  between  it  and  the  ridge 

would  give  the  edge-cut.     If 

the    hip    rafter    is    nearly 

vertical,  then  the  same  plan 

represents    the    plan    of    a 

triangle  having  the  line  ab 

horizontal  and  the   point  C 

much    higher,   as  shown   in 

Fig.  490.      This  true  shape, 

which  gives  the    angle  for 

the  edge-cut,    is    found    by 

revolving  the  triangle  until 

it  is  horizontal,  the  angle  at 

C  being  the  one  required. 

In  Fig.  491,  the  hip  rafters 
meet  together  upon  the  end 
of  the  ridge.  The  figure  cut 
off  above  the  horizontal  line 
is  in  this  example  a  four- 
sided  one,  and  the  same 
method  of  determining  its 
true  shape,  and  therefore  the 
bevels  to  which  the  end  must 
be  cut,  is  adopted. 

The  lengths  and  bevels  of 
valley  rafters  are  obtained 
in  the  same  manner  as  with 
hip  rafters,  the  only  differ- 
ence being  that  there  is  no 
angle  tie  or  dragon  piece 
needed  at  the  lower  end. 

It  is  often  necessary  to  cut         pio.  492.— Method  of  obtaining  Bevels 

the  upper  edge  of  the  hip  jj  ^^lic  ""Liters"**  *^""'"^  *^^^*  ^^^ 
rafter  so  that,  from  its  centre 

line,  it  is  in  the  planes  of  the  roof  surfaces.  This  is  technically 
termed  "  backing "  the  hip  rafter.  In  Fig.  485,  ^  shows  in 
each  case  the  bevels  required  in  backing  the  hip  rafter.  To 
obtain  these,  draw  any  line  ah  at  right  angles  to  the  plan  of 
the  hip  rafter;  where  this  line  cuts  the  centre \m^  oi  \)aft\iv^  «» 


Developed 
side  ^F  Purlin 


Developed 

edgeoF 

Purtfn.; 


232       A  MANUAL  OF  CARPENTBY  AND  JOINERY. 

at  o,  draw  a  lin 

rafter.     With  o 

litieof  the  hip  rafter  a  length  oO  equal  to  the  altitude  oc' ;  join 
aC  and  bC.  The 
angle  aGb  is  the  in- 
clination  of  the  roof 
aurfacea  to  each  other, 
and  therefore  of  the 
"  backed  "  upper  aur- 
facea  of  the  rafter. 

Bevels  of  Pol'lllll 
agaiiut  Sip  Baflon.— 
The  lengths  of  pur- 

aliDost  always  hori- 
zontal— can  be  found 
from  the  plan,  while 
the  bevels  to  which 
the  ends  require  cut- 
ting to  fit  against 
hip  rafters  are  shown 
in  plan  when  the 
purlins  are  fixed  on 
edge — that  is,  with 
the  side  of  the  purlin 
vertical.  With  pur^ 
this  position 


the 


cut 


"  square. 

When  the  edge  is 
parallel  to  the  slope 
of  the  common  rafter, 
the  end-bevels  pre- 
sent more  difficult}'. 
Fig.  492  shows  how 


the  8 


bevel 


obtained.  A  plan  giwes  the  true  length  of  each  edge  of  the 
purlin,  and  ahowa  how  much  ahorter  ja-  in  than  yff,  and  how 
much  longer  zz  is  than  y}/  (Fig.  485) ;  but  the  plan  does  not  show 
the  exact  width  of  either  the  side  rx  i/>/,  or  the  edge  iz  yy.  It  is 
ia  the  section  that  the  true  width  of  these  surfaces  is  seen,  the 


WOODEN  ROOT'S.  233 

width  of  the  plan  depending  npon  the  inclination  of  the  roof. 
By  "developing"  or  turning  the  widths  aa  Been  in  section 
until  they  are  hori^Dntal,  tliun  projecting  th»m  to  the  plan, 
and  carrying  the  points  j:  and  s  to  the  projected  linea,  the 
bevels  are  obtained.  An  enlarged  sactioa  of  tk  purlin,  with 
the  plan  showing  the  angle  at  which  the  end  of  the  purhn 
meets  the  hip  rafter,  is  shown  in  Fig.  492.  By  following  this 
method  it  ia  possible  to  obtnin  the  eud-bevela  of  purlins  without 
confuuion,  even  with  a,  roof  having  many  diSei'ently  inclined 
surfaces.  In  all  cases,  it  is  best  to  di'aw  out  to  a  lai'ge  scale  a 
<^ross-sectton  of  the  common  rafter  and  purlin  in  position  ;  to 
project  fiYim  these  the  plan  of  the  purlin  meeting  the  hip 
mfter — which  may  be  shown  by  a  single  line— at  the  angle 
indicated  in  the  "roof  plan";  and  to  draw  the  developed 
surfaces  as  in  Fig.  492. 

Lengths  and  Bavels  of  Jack  Raftars. — The  side-cuts  of  jack 
rafters  have  the  same  bevels  as  those  of  the  common  rafters.  If 
the  hip  rafter  against  which  they  abut  bisectA  the  angle,  then 
the  jack  raftera  on  each  side  of  this  hip  rafter  are  similar.  Tlie 
lengths  we  determined  by  projecting  the  plan  of  each  to  the 
section,  as  shown  in  Fig.  485  at  MIf.  The  edge-cut  is  found  by 
developing  the  roof  surfaces  as  shown  in  Fig.  493.  In  this  figure 
each  surface  is  turned  about  the  ridge,  and  the  angles  marked 
F  give  the  bevels  for  the  edge-cut  in  each  case. 

It  will  also  be  seen  that  as  these  developed  surfaces  aj'e  the 
actual  roof  surfaces  turned  horizontally,  the  area  of  the  surface 
of  the  roof  will  be  obtained  by  measuring  them.  The  end-bevels 
for  the  roof  boarding  are  also  shown  at  O. 

Turret  Roofe.— Fig. 494  shows  the  plan  and  sectional  elevation 
of  a  small  turret  roof,  the  plan  of  which  is  a  regular  hexagon. 
On  it  are  shown  the  lengths  and  bevels  of  the  hip  and  jack 
rafters,  the  backing  of  the  hip  rafter,  and  the  development  of 
one  triangular  face.  The  same  index  letters  are  used  as  in  the 
previous  examples  ;  the  bevels  will  therefore  be  understood 
readily.  Eoofs  of  this  description  are  used  generally  for  orna- 
uienting  the  comers  of  a  building,  or  as  roofs  for  ventilators. 
The  exposed  positions  in  which  they  are  placed  render  it 
necensary  that  they  should  be  well  braced  and  anchored  to  the 
building.  This  latter  necessity  is  provided  for  by  passing  long 
bolts  through  angle-tie:<  at  each  corner  to  holdfasts  driven  into 
the  wftU  aeverat  feet  below  the  eaves  level 


26*       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

A  turret  roof  having  a  curved  roof  surface  is  shown  in  plan 

and  sectional  elevation  in  Fig.  495.  Tlie  outline  of  the  jack 
raftera  is  shown  in  the  sectional  elevation.  The  shape  of  the 
hip  rafter,  which  is  also  shown  on  the  drawing,  is  obtained  hy 
taking  a  number  of  pointe  I'  to  7'  in  the  sectional  elevation, 
projecting  from  these  pointa  to  the  plan,  and  from  the  plaji  of 


Fio.  494.— Plan  and 


Ptg.  4650 


one  of  the  hip  rafters  cut  by  projectors  from  these  points, 
erecting  perjiendicular  lines  on  which  corresponding  heights  I' 
to  7'  are  taken.  A  freehaiid  curve  drawn  through  the  pointa 
thus  obtained  gives  the  outline  of  the  hip  rafter. 

The  developed  roi)f  surface  is  obtained  by  taking  the  same 
points  r  to  7' — measured  along  the  curved  line  in  elevation — 
and  drawing  a  "stretch-out"  so  that  projectora  from  the  same 
points  in  plan  will  give  the  width  at  the  respective  heights. 


WOODEN  ROOFS. 


By    drawing     freeliand     curves     through     these    points,    the 
developed  roof  surface  ia  obtaioed. 


Sninnuuy. 

Vooden  rooft  may  be  lean-to  or  rid/jed  roofs. 

The  slatM  or  tiles  oF  a,  sloping  roof  n,ro  carriod  by  eommon  rr^flers 
which  rest  on  purliiu*.  In  dwelling-bimsea  the  inner  walls  are 
generally  sufficiently  neiir  each  other  to  support  the  purlins.  In 
larger  buildings  the  purlins  are  carried  by  tnmme  placed  from  S  to 
10  feet  apart.  Purlins  should  not  bo  more  than  8  foet  apart,  and 
when  tniBses  arc  used  they  should  ho  so  designed  as  directly  t 
■upport  each  purlin.     The  shape  uf  the  trussea  va 


^6      A  MANUAL  O^  CARPENTHY  AND  JOINERY. 

the  width  between  the  walls  and  the  outline  of  the  roof.  The 
principal  types  of  trusses  are  named  collar-beam,  King-posit  Queen- 
post,  combination  (wood  and  iron),  latticed,  Mansard,  and  Gothic, 

All  the  Joints  in  roof  trusses  should  be  so  made  as  to  be  unaffected 
by  shrinkage  of  the  timber. 

The  eaves  of  the  roof  may  overhang,  or  gutters  of  cast  iron  or  lead 
may  be  formed  behind  parapet  walls. 

The  len^rths  and  bevels  of  the  oblique  cuts  in  hipped  roofs  may  be 
obtained  by  applied  practical  geometry. 

Flat  roofs  may  be  covered  with  lead,  zinc,  or  some  bituminous 
substance.  Their  construction  is  similar  to  that  of  a  floor,  with  the 
exception  of  the  slight  "  fall "  required. 


Questions  on  Chapter  IX. 

1.  Make  a  line  diagram  and  write  the  names  of  the  parts  of  a 
collar-beam  roof  of  16  ft.  span,  and  show  by  line  diagrams  the  form 
of  principal  (truss)  you  would  use  for  a  25  ft.,  35  ft.,  and  a  50  ft. 
span  roof.  Show  the  parts  in  compression  by  single  lines,  and 
those  in  tension  by  double  lines.     (C.  and  G.  Ord.,  1898.) 

2.  Make  a  drawing  of  rather  more  than  half  of  a  simple  King- 
post truss  for  a  roof,  the  span  of  which  is  25  ft.  Scale  ^  in.  to  1  ft. 
(C.  and  G.  Prel.  1904.) 

3.  Make  a  drawing  of  rather  more  than  one-half  elevation  of 
a  roof  truss  of  30  ft.  span  ;  scale  J  in.  to  1  ft.  Dimension  and  name 
the  parts,  and  make  freehand  sketches  of  the  joints  used.  (C.  and 
G.  Ord.,  1900.) 

4.  Draw  to  a  scale  of  one  and  a  half  inches  to  a  foot,  three 
methods  of  forming  the  joint  between  a  principal  rafter  and  a  tie- 
beam.     (C.  and  G.  Ord.,  1896.) 

5.  Draw  to  a  scale  of  one  and  a  half  inches  to  a  foot,  three 
methods  of  securing  with  iron  the  foot  of  a  principal  rafter  to  a  tie- 
beam.     (C.  and  G.  Ord.,  1896.) 

6.  It  is  required  to  cover  a  building  28  ft.  by  42  ft.  with  a  tiled 
roof.  Show  by  plan,  to  scale  ^  inch  to  a  foot,  where  you  would 
place  the  roof  trusses ;  and  give  to  a  scale  of  ^  inch  to  a  foot  the 
elevation  of  half  of  one  truss.     (C.  and  G.  Ord.,  1896.) 

7.  It  is  required  to  cover  a  building  40  ft.  wide  with  roof  in  one 
span  and  ^  pitch.  Give  elevation  of  the  truss  you  would  use  to 
scale  4  ft.  to  an  inch.     (C.  and  G.  Ord.,  1897.) 

8.  Give  enlarged  details  of  joints  to  the  foregoing  roof  (Q.  7) 
in  isometrical  projection,  showing  the  ironwork  you  would  use. 
(C.  and  G.  Ord.,  1897.) 


QUESTIONS  ON  CHAPTER  IX.  257 

9.  Draw,  to  a  scale  of  §  in.  to  one  foot,  the  elevation  of  about 
ono-half  of  a  roof  truss  for  a  building  30  ft.  wide  (inside  measure- 
ment). The  principal  rafters  and  the  collar  beam  are  to  be  of 
wood,  and  the  tie-  and  King-rods  to  be  of  iron.  Give,  to  a  scale  of 
1)  in.  to  one  foot,  the  details  of  the  joints. 

10.  Draw,  to  a  scale  of  1^  in.  to  one  foot,  alternative  vertical 
cross  sections  through  the  eaves  of  a  roof  showing  : 

(a)  the  eaves  overhanging  18  in.,  and  finished  with  fascia  board, 

cast-iron  gutter,  and  soffit  boarding ; 
(6)  a  parallel  gutter  behind  a  stone  cornice  and  blocking  course ; 

(c)  a  tapering  lead  gutter  behind  a  brick  parapet  wall ; 

(d)  a  cast-iron  gutter  behind  a  brick  parapet  wall. 

11.  An  open  void  in  a  roof  is  7  ft.  by  4  ft.  Show  how  you  would 
"  trim"  round  it.     (C.  and  G.  Ord.,  1901.) 

12.  Draw  to  a  scale  of  i  inch  to  a  foot,  a  roof  truss  to  a  span  of 
20  ft.  so  as  to  form  as  large  a  room  as  possible  in  the  roof.  (C.  and 
G.  Ord.,  1895.) 

13.  Make  a  half  elevation  of  a  Mansard  roof  truss  of  38  ft.  span  ; 
scale  J  in.  to  the  foot.  Mark  on  the  dimensions  of  the  several 
parts,  and  make  freehand  sketches  of  the  joints  used  in  con- 
struction.    (C.  and  G.  Ord.,  1899.) 

14.  Draw  the  elevation  of  a  light  roof- truss  for  a  temporary 
building,  the  width  to  be  30  ft.  in  the  clear,  and  the  trusses  to 
occur  every  8  ft.  to  have  a  semi-circular  built  up  rib,  the  springing 
being  7  ft.  6  in.  above  the  floor.  The  roof  may  be  covered  with 
light  boarding  and  corrugated  iron.     (C.  and  G.  Hon.,  1904.) 

15.  A  public  hall,  50  ft.  wide,  is  to  be  roofed  in  one  span  by 
either  a  hammer-beam  roof  or  a  collar-beam  roof.  The  whole  roof 
is  to  be  seen  as  part  of  the  interior,  and  the  ribs  to  be  moulded, 
spandrels  ornamented,  etc.  Draw  to  a  scale  of  4  ft.  to  1  in.  rather 
more  than  half  the  elevation  of  a  suitable  timber  truss,  and  furnish 
sketches  to  a  larger  scale,  or  in  perspective,  of  the  joints,  ironwork, 
and  other  details.  The  material  to  be  pitch  pine.  (C.  and  G.  Hon. , 
1903.) 

16.  Draw  to  scale  of  1  in.  to  a  foot  the  foot  of  a  hammer-beam 
truss,  40  ft.  span  and  ^  pitch ;  dot  outline  of  tenons  and  show  the 
bolts  and  straps.  The  hammer-beam,  with  all  work  below  it,  and 
the  ends  of  timbers  framed  above,  to  be  shown.  (C.  and  G.*  Hon., 
1897.) 

17.  Draw  rather  more  than  half  elevation  of  a  hammer-beam  roof 
of  35  ft.  span.     (C.  and  G.  Hon.,  1904.) 

18.  Draw  to  a  scale  of  1  in.  to  a  foot,  half  (at  least)  of  the 
elevation  of  a  hammer- beam  truss  for  the  roof  oi  a  smaW.  c\v\rcOa.^  \a 


^8       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

be  executed  in  oak.  Show  the  joints  and  any  ironwork  introduced, 
by  sketches,  to  a  larger  scale,  or  in  perspective.  (C.  and  G.  Hon., 
1901.) 

19.  Make  drawings  of  a  dragon  tie.  Show  how  you  would 
determine  the  length  of  a  hip  rafter,  the  angle  at  the  back  of  the 
hip  rafter,  and  the  bevels  for  purlins  and  jack  rafters.  (C.  and  G. 
Ord.,  1904.) 

20.  Draw  to  a  scale  of  1^  in.  to  a  foot  plan  and  elevation  of  an 
angle  tie  and  dragon  piece,  and  show  how  you  would  obtain  the 
bevels  of  hip  rafter.     (C.  and  G.  Ord.,  1897.) 

21.  A  hipped  roof  is  inclined  at  the  angle  of  30°.  Find  the 
angles  necessary  for  cutting  the  hip  rafters,  purlins,  and  jack 
rafters.     (C.  and  G.  Ord.,  1903.) 

22.  Make  a  drawing  showing  how  you  would  find  the  different 
bevels  for  a  valley  rafter.     (C.  and  G.  Ord.,  1900.) 

23.  Explain  with  sketches  how  you  would  construct  the  angle  of 
a  hipped  mansard  roof,  and  give  the  bevels  for  the  various  outs. 
(C.  andG.  Ord.,  1895.) 

24.  Make  a  drawing  of  sufficient  of  the  plan  and  elevation  of  an 
octagonal  dome  8  ft.  in  diameter  boarded  internally.  All  the 
applied  geometry  should  be  clearly  shown  in  the  drawings.  (C.  and 
G.  Hon.,  1900.) 

25.  Make  the  drawings  of  an  octagonal  pyramidal  turret-shaped 
roof;  span  45  ft.,  height  46  ft.  All  timbers  to  be  shown  and 
dimensioned,  and  the  geometrical  method  of  obtaining  the  angles  of 
the  backs  of  rafters,  purlins,  etc.,  should  be  shoAvn.  Part- only  of 
the  plan,  elevation  and  section  should  be  drawn.  (C.  and  G.  Hon., 
1901.) 


CHAPTER   X. 

PARTITIONS  AND  WOODEN  FBAMED   BUILDINGS. 

Partitions. — It  is  often  inconvenient  to  have  the  upper  rooms 
of  a  building  of  the  same  size  and  shape  as  the  lower  rooms. 
In  such  cases  the  walls  which  divide  the  lower  rooms  from  each 
other  cannot  be  carried  upwards  to  form  the  divisions  of  the 
higher  rooms.  For  various  other  reasons  it  may  be  undesirable 
to  continue  brick  division-walls  to  the  upper  storeys.  The 
rooms  of  the  upper  storeys  may,  however,  be  separated  by 
partitions  of  wood  and  plaster. 

A  frequently  adopted  means  of  forming  such  partitions  is 
to  fix  upright  pieces  of  wood  named  studs  in  the  same  vertical 
plane  at  distances  of  from  twelve  to  fifteen  inches  apart. 
Wooden  laths,  which  carry  the  plaster,  are  nailed  to  both  sides 
of  these  studs.  As  a  further  means  of  stiffening  them,  short 
horizontal  pieces  of  wood,  3"  by  1^",  called  nogglng  iiieces,  are 
fitted  and  nailed  between  the  studs,  in  rows,  at  distances  of 
about  four  feet  in  height.  This  method  of  arranging  studs  has, 
however,  the  disadvantage  of  throwing  the  whole  of  the  weight 
of  the  partition  on  the  floor  on  which  it  rests  ;  and  any  settle- 
ment or  "  sagging "  of  the  floor  naturally  strains  the  partition, 
and  tends  to  crack  the  plaster. 

As  the  studs  and  other  pieces  of  timber  used  in  framing  are 
of  section  known  as  quartering,  such  partitions  are  known 
as  quartered  p9xtition8.  These  partitions  are  usually  from 
3"  to  4j"  thick,  and  the  studs  used  are  generally  2"  wide.  It 
is  necessary  to  have  all  the  members  of  the  same  partition 
of  the  same  thickness  to  enable  both  sides  to  be  plastered 
evenly. 


260      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


\'^ 

^ 

i 

^ 

\ 

\ 

1 

iA 

1 

i. 

y'' 

0  436.— LlnDdagTsmors 


Btruct  the  partition 
as  a  framework,  or 
trnao,  bo  arranged 
that  the  whole 
weight  of  the  par- 
tition is  directly 
transmitted  to  the 
walk.  rig.  496  is 
a  line  diagram  of 
a  bamed  partttion 
without  any  door- 
way. Each  mem- 
I  shown  by  a 


single  line.    Fig.  497  shows  the  elevation  of  a  framed  partition 
with  a.  central  doorway,  seven  feet  high  and  three  feet  wide,  and 


El£7AT10H  of^t/mED  Pahtitiqn. 


has  the  names  uf  the  various  parts  indicated.     In  this  case  the 
partition  ruue  in  the  direction,  of  the  floor  joists  of  the  lower 


PARTITIONS  AND  WOODEN  FRAMED  BUILDINGS.     261 


floor,  and  the  sill,  which  is  in  one  length,  is  arranged 
between  two  joists.  The  upper  floor  joists  are  at  right 
angles  to  the  partition,  and  are  supported  by  it. 
The  stronger  members  of  these  partitions — that 
is,  the  bead,  sill,  door-posts,  and  braces — are  first 
framed  together,  the  joints  being  secured  with 
iron  bolts  or  straps ;  the  intermediate  spaces  are 
then  filled  with  studs  placed  from  twelve  to  fifteen 
inches  apart.  Each  brace  should  always  be  in  one  length,  with 
the  studs  cut  to  fit  on  it.  All  the  joints  should  be  arranged  so 
that  they  are  as  little  as  possible  affected  by  shrinkage,  and  all 


Fig.  498. 


Section 


k 


''-^ 


%"bolt 
Stonetemplai  ^  y^  ^/y% 


Fio.  499. 


Fio.  500. 
Joint  at  Foot  of  Braco. 


"////  O 
V^^//'^^ 


^< 


the  thicker  members  of  the  partition,  such  as  door-posts,  braces, 
etc.,  should  have  the  corners  taken  off  (Fig.  498).  Seasoned 
timber  should  always  be  used  in  the  construction  of  partitions, 
either  red  deal  or  white  deal  generally  being  used. 

Joint  at  Foot  of  Brace. — Fig*.  500  shows  in  elevatioii  \Xi^  \cim\i  ^\> 


202       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


the  foot  of  the  brace.  The  joint  may  be  bridled,  as  in  Fig.  501, 
or  may  be  lialved  on  (Fig.  602).  In  either  case  a  bolt  is  neces- 
sary to  secure  the  connection. 


Bridtejoint 


FiQ.  501.— Bridle  Joint. 


FiQ.  502.— HalvedJoint. 


-suia 


Nails 


Joint  l>etween  Stud  and  Brace. — This  joint  may  be  simply  cut 
to  the  required  bevel  and  nailed  (Fig.  503),  or  it  may  be  cut  as 

shown  in  Fig.  500. 

Joint  between  Stud  and  SilL — This 
joint  is  made  by  a  short  tenon 
(named  a  stump  tenon)  on  the  stud 
fitting  into  a  corresponding  mortise 
in  the  sill  (Figs.  499  and  600).  The 
ends  of  the  door-posts,  as  well  as  the 
upper  ends  of  the  studs,  are  also 
stump-tenoned  into  the  head  or  sill  as 
the  case  may  be. 

Joint  at  Head  of  Brace. — In  Fig.  50r) 
the  door-post  is  wider  above  the  door- 
head  to  allow  for  the  abutment  of  the 
brace.  This  arrangement  necessitates 
increased  labour  as  well  as  a  waste 
of  material.  An  alternative  method 
is  to  let  in  a  cleat  and  nail  it  to  the  door-poat.  The  upper 
end  of  the  brace  abuts  against  this  cleat  (Figs.  497  and  604). 
The  door-head  is  stump- tenoned  into  the  door-post  as  shown 
in  Figs.  504  and  505. 

Joint  at  Head  and  Foot  of  Door-post. — When  the  sill  runs 
"straight  through"  as  in  Figs.  497  and  510,  the  lower  end  of 
the  door-post  is  stump-tenoned  into  it,  and  may  be  secured  with 


Fia.  503.— .Joint  between  Stud 
and  Bnu'e. 


PARTITIONS  AND  WOODEN  FRAMED  BUILDINGS.     263 

joint  bolt,  as  shown   in  elevation  and  section  in  Figs.  506 
d  507.     Or,  it  may  have  a  wrought-iron  strap  to  clip  the 


c-^j/-^ 


3^  doorhead^ 


FiQ.  504. 


Fia.  505. 


Alternative  Joints  at  Head  of  Brace. 


I  and  door-posts,  with  bolts  passing  through  to  fasten  the 
nt.     Tlie  objection  to  this  latter  method  is  that  the  bolts  are 


4 

H 

I 
I 
I 
I 

I 
I 


^ 

I 


L-^ 


Joint  bolt 


Fio.  600. 


I  • 


1 1 


I 
I 


housedjoinl 


I 


^Floorjoists 

Fio.  508. 


Altcni&tiwQ  Jomts  at  Foot  of  Boor-^ost, 


26*      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

liable  to  be  in  the  way  of  the  laths  and  plaster.  The  atump- 
tenon  and  joint  bolt  are  also  used  to  secure  the  upper  end  d 
the  door-poat  to  the  head  (Fig.  497).  When,  aa  frequently 
happens,  the  partition  runa  across  the  joists  of  the  lower  floor, 
the  sill  caonot  be  continuous  on  account  of  the  doorways 
(Figs.  509  and  612).  In  such  circuniatances  the  aill  is  sunk  or 
housed  into  the  door-posta,  these  latter  going  between  the  joiats, 
as  shown  in  Fig.  508. 

Partition  with  Two  Side  Doorways.— Fig.  509  is  the  eleva- 
tion of  a  partition  with  two  side  doorways.    The  horizonlal 


FuL  509.— FSTtition  nlth  Two  Side  DoomufB. 

njeniber,  which  is  continuous  and  forms  the  door-head,  is  named 
an  Intertle,  and  acts  in  this  example  as  the  main  support  of  the 
partition.  A  long  wrought-iron  bolt,  one  inch  in  diameter,  and 
having  a  nut  at  each  end  for  tightening  up,  passes  through  the 
centre  of  the  partition,  as  shown  in  the  illiatration.  A  strong 
wooden  member  might  l>e  substituted  for  the  bolt,  with  the  ends 
stump-tenoned  into  the  head  and  sill,  and  the  joints  secured 
with  joint  bolts  in  a  manner  similar  to  the  joints  shown  at  the 
head  of  the  door-posts  (Fig.  497). 

Figs.  510  and  511  are  diagrams  of  otHer  framed  and  bncad 
partitions.  In  these,  the  stronger  fi'aming  is  shown  by 
double  lines,  while  the  atuda  and  horizontal  nogging  pieces  are 
iadicated   hy   single  lines.     Tliese  di^i-ama   represent   typical 


PARTITIONS  AND  WOODEN  FRAMED  BUILDINGS.     265 


examples  of  the  manner  in  which  partitions  are  trained.  The 
size  and  arrangement  of  the  framing  are,  of  course,  dependent 
upon  the  width  of  span  between  the  walls,  on  the  nuniljer,  size, 


y\ 

W[ 

s 

/' 

s 

■    ■ 

s 

1 

Line  DlagmnB  of  Pramsd  and  Trussed  Partitions. 

and  position  of  doorways,  and  on  the  number,  if  any,  of  floors 

to  be  supported  by  the  partition.    Fig.  512  shows  a  partition  ■ 

extending  through  two  storeys  in  height,  with  a  wide  central 

doorway   id    the  upper 

part,  and  two  smallerside 

doorways  m  the  lower 

part.    The  joints  of  these 

partitions  are  arranged 

on  the  principles  given 

iu    detail     above,    and 

therefore   do  not   need 

further  explanation. 

Brick-nogging.— The 
timber  partitioD,  instead 
of  having  tbe  studs 
placed  to  carry  laths 
and  plaster,  may  be  fiieii 
at  intervals  of  from  two 
feet  three  inches  to  three 
feet,  and  the  intervening 
space  filled  with  brickwork.  Horizontal  nogging  pieces  of 
wood,  one  inch  thick,  should  be  inserted  at  every  third  or 
fourth  course.  The  usual  thickness  for  brick-nogged  partitions 
is  four  and  a  half  inches,  though  often  for  the  sake  of  economy, 
or  to  gain  room,  they  are  made  three  inches  thick,  in  which 
cue  the  bricks  are  laid  on  edge  between  the  etuda. 


Fio.  SI!. -Two- 


A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


WOODEN  FRAMED  BUILDINGS. 


of  buildings  of  a.  temporary  character.  The  framework  may  1 
covered  with  either  boards  or  corrugated  iron.  In  varioi 
parte  of  the  world,  dwelling  houBes  are  conetruoted  in  th 
manner,  but  in  this  country  wooden  framed  buildings  ai 


confined  to  such  structures  as  small  railway  stations,  exhibition 
buildings,  portable  workshops  and  sheds,  temporary  warehouses, 
cricket  and  football  pavilions,  etc. 

General  Principles  of  Oonstractlon.— The  general  arrange' 
meat,  of  course,  depends  upon  special  circumstances,  while  the 
dimensions  of  the  framing  and  the  methods  of  bracing  it 
together  are  influenced  by  the  size  of  the  building,  and  the  uses 
to  which  it  is  to  be  put.  The  usual  arrangement  of  such  timber 
structures  is  to  have  heavy  sq^uare  angle  posts,  with.  lntenn»dluy 


WOODEN  FRAMED  BUILDINGS.  267 

posts  if  necessary,  and  between  these  to  insert  cross  rails  and 
diagonal  braces.  The  main  braces  should  by  preference  be 
continuous,  in  order  to  brace  the  structure  rigidly,  any  abutting 
cross-rails  being  cut  to  fit  them.  The  joints  used  are  similar 
to  those  already  described,  and  include  the  mortise  and  tenon, 
the  bridle,  and  halved  joints,  care  being  taken  to  arrange  them 
so  that  they  are  least  affected  by  shrinkage.  Bolts,  joint  bolts, 
coach  screws,  iron  straps,  and  wooden  pins,  are  used  as  fastenings 
according  to  requirements.  If  the  building  is  more  than  one 
storey  high,  it  is  necessary  to  make  provision  in  the  framing 
for  supporting  the  upper  floor.  When  window  or  door  openings 
occur  in  such  a  building,  it  is  advisable  to  have  them  directly 
over  each  other  whenever  possible. 

Wooden  structures  of  this  description  should  always  rest 
upon  a  foundation  of  brick  or  stone- work  or  concrete,  so  that 


Fio.  614. — Tongued,  Grooved  and  Beaded  Battens. 

all  timber  is  at  least  12  inches  from  the  ground.  A  layer  of 
some  bituminous  substance,  which  serves  as  a  damp-proof  course, 
will,  when  laid  upon  the  foundation  prevent  the  wood  from 
absorbing  moisture  out  of  the  earth.  When  a  wooden  ground- 
floor  is  used — as  is  often  the  case — every  care  should  be  taken  to 
have  a  free  circulation  of  air  under  the  floor  to  prevent  dry  rot. 
When  this  class  of  building  is  to  be  of  a  portable  nature,  it  may 
be  built  in  sections,  with  the  various  parts  fastened  together 
with  bolts,  joint  bolts,  or  screws.  Temporary  buildings  are 
most  economically  constructed  out  of  marketable  sections  of 
deals  and  battens.  Heavy  supporting  posts  may  be  formed  by 
bolting  two  or  three  deals  together. 

Covering  Materials.  —As  previously  stated,  the  covering  of 
the  framework  may  be  either  wood  or  comig^ated  galvanized  iron. 
When  the  framing  is  covered  with  wood,  the  covering  boards 
may  be  fixed  vertically  with  match-boarding  joints,  that  is, 
either  tongued,  grooved  and  beaded  (Fig.  514),  or  rebated 
(Fig.  515),  or  with  square-edged  joints  covered  by  narrow 
laths  or  fillets  oi  wood  as  shown  in  ¥ig.  5\(3.    Oy.,  \X\^  \icy^\\^ 


268       A  MANUAL  OF  CARPENTKY  AND  JOINERY. 

may  be  placed  horizontally  with  joints  as  shown  in  Figs.  619 
and  620;  this  class  of  boarding  is  known  as  weather  hoarding. 
Corrugated  galvanized  iron  sheets  are  used  as  a  more  perma- 
nent covering  than  wood ;  the  sheets  are  secured  to  the  framing 
with  screws  and  washers. 

In  the  inside  of  the  building,   the  framing  is  either  left 
exposed  without  covering,  is  boarded  with  match  boarding,  or 


Fia.  515.— Rebated  and  V-joiuted  Battens. 

is  plastered,  according  to  the  finish  required.  Some  such 
buildings,  in  addition  to  being  lined  inside  with  boards,  have  a 
layer  of  felt  or  "  Willesden  paper "  behind  the  boarding  as  a 
means  of  warmth.  The  roofs  of  such  buildings  may  be  covered 
with  boards,  boards  overlaid  with  f^t,  corrugated  iron,  slates, 
or  tiles,  and  the  construction  follows  the  principles  already 
explained  in  Chap.  IX. 

It  is  obvious  that  in  such  wooden  buildings  there  is  consider- 
able scope  for  ornamental  treatment  in  cases  where  an  attractive 


Fio.  616.— Square-edged  Battens  with  Fillets  over  Joints. 


appearance  is  of  importance,  as  for  example,  in  exhibition 
buildings,  cricket  pavilions  (Fig.  513),  etc.  On  the  other  hand, 
in  warehouses  (Fig.  517),  workshops,  and  the  like,  decorative 
treatment  is  of  small  consequence,  and  strength  and  rigidity 
are  the  main  considerations. 

Half  Timber  Work. — A  style  of  architecture  which  presents 
a  picturesque  appearance,  and  is  frequently  adopted  in  villas 
and  country  residences,  is  known  as  half  timber  work.  Some  of 
the  older  examples  of  this  work  show  the  walls  of  the  building 
constructed  entirely  with  wooden  framing,  the  spaces  between 
which  are  fiiJed  in  with  brickwork,  to  form  slightly  recessed 


WOODEN  FRAMED  BUTLDTNGS.  26!I 


Tyi>ca"l*-ottflicil 


270       A   MANUAL  OF  CARPENTRY  AND  JOINERY. 


Kxa    v'o"  "'  "  \S  T  n  \bi  ft  ftSVMS^ 


WOODEN  FRAMED  BUILDINGS.  271 

pa,nelH,  the  surface  of  the  brickwork  generalty  being  plastered. 
Kfr>re  modern  e^caniples  have  the  lower  storey  built  of  stone  or 
brick,  with  only  the  upper  walls— hdf  in  some  caees  only  the 
gablea— of  half  timber  work  (Figs.  524  and  523). 

In  the  best  examples  of  half  timber  work  it  is  usual  to  have 
stout  comer  ponta  of  quartering,  into  which  are  framed  the 
necessary  head,  sill,  and  cross-rails,  with  intermediate  framing 
of  the  required  design.    The  joints  are  chiefly  mortise  and 


irnplSH  ot  Bair ' 


t«non,  held  together  with  hard-wood  pins  {t?umaili).  The  spaces 
between  the  framing  are  fliled  in  with  bricl^work,  which  is  set 
back  for  about  ]  J"  from  the  face  of  the  framing  so  that  when  the 
surface  of  the  brickwork  is  plastered  it  forma  recessed  panels 
about  three-quarters  of  an  inch  deep.  The  finished  surface  of 
the  plaster  may  be  either  smooth  or  rough  cast.  To  obtain  & 
sufficient  thickness  of  wall,  additional  brickwork — bonded  with 
the  rest — is  built  behind  the  wooden  framing. 

The  best  timber  for  this  work  is  oak,  although  pitch  pine  and 
red  deal  are  also  used.  £ed  deal  is  better  than  pitch  pine  as  it 
is  not  soliable  to  crack  on  exposure  to  the  weSytWc. 


272       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

For  the  sake  of  economy,  modifications  of  half  timber  work 
are  often  used  which,  although  preserving  the  same  outward 
appearance,  have  nothing  to  commend  them  but  cheapness. 
One  of  these  consists  of  using  framing  as  described  above  and 
filling  in  the  spaces  with  vertical  studs  and  lath  and  plaster. 
Another  method  is  to  fix  thin  frames  of  timber,  not  more  than 
1  J"  thick,  against  the  face  of  the  brick  wall,  and  to  plaster  the 
recessed  panels  as  described  above. 


Summary. 

PartitioxLS  of  wood  covered  with  laths  and  plaster  often  take  the 
place  of  brick  walls  between  upper-storey  rooms.  Such  partitions 
are  best  framed  into  trusses  directly  transferring  the  weight  to  the 
walls. 

The  firamework  consists  of  horizontal  members  {headj  siU,  and 
irUertie)^  vertical  members  {door-po8t8  and  stvda),  and  of  inclined 
braces.  All  the  members  of  the  same  truss  should  be  of  the  same 
thickneaa  to  enable  both  sides  to  be  plastered  evenly. 

Horizontal  nogging  pieces  are  fixed  at  intervals  to  stifien  the 
studs.  The  joints  mostly  used  for  the  framework  of  partitions  are 
the  stump  tenon  and  the  bridle  joints,  secured  with  bolts. 

Brick-nogging  consists  of  filling  in  the  wooden  framework  with 
bricks. 

Structures  such  as  exhibition  buildings,  temporary  workshops  and 
warehouses,  etc.,  often  consist  entirely  of  wooden  firaming  covered 
with  boards  or  corrugated  galvanized  iron.  Such  buildings  should 
always  rest  upon  a  base  of  brickwork  or  concrete. 

In  half  timber  work  the  spaces  between  the  exposed  wooden 
framing  are  filled  with  brickwork,  the  surface  of  which  is  covered 
usually  with  cement  plaster. 


Questions  on  Chapter  X. 

1.  Draw  rather  more  than  half  the  elevation  of  a  framed  and 
trussed  partition,  16  ft.  6  in.  by  12  ft.  6  in.  in  size,  having  a 
central  door-opening  8  ft.  9  in.  wide  and  7  ft.  6  in.  high.  The 
partition  is  to  be  supported  at  its  ends,  and  is  to  carry  the  weight 
of  the  floor  above  it.     (C.  and  G.  Ord.,  1903.) 

2.  Draw  a  framed  and  braced  partition  supported  only  at  the  ends, 
the  head  carrying  floor  joists,  to  measure  17  ft.  by  11  ft.,  with  two 

door  openingB,  each  3  ft.  3  in.  by  6  it.  9  m.,  aud  within  2  ft.  6  in. 


QUESTIONS  ON  CHAPTER  X.  273 

of  the  end  of  the  partition  in  each  case.     Figure  scantlings.    (C.  and 
G.  Ord.,  1901.) 

3.  A  framed  and  braced  partition,  16  ft.  3  in.  by  12  ft.,  has  two 
door-openings,  each  7  ft.  by  3  ft.  2  in.  One  is  in  the  centre  of  the 
partition  and  one  at  the  end.  The  partition  is  supported  at  the  ends 
and  is  to  carry  floor  joists.  Make  a  drawing  of  this  partition  and 
dimension  the  scantlings.     (C.  and  G.  Ord.,  1902.) 

4.  Draw  the  elevation  of  rather  more  than  half  of  a  framed  and 
trussed  partition,  showing  the  method  of  construction.  The 
partition  is  25  ft.  by  12  ft. ,  and  contains  three  doorways,  each  3  ft. 
by  7  ft.  A  doorway  is  to  be  placed  18  in.  from  each  end,  and  one 
in  the  centre.  The  partition  will  be  required  to  carry  its  own 
weight,  together  with  the  weight  of  the  floor  above.  (C.  and  G. 
Ord.,  1904.) 

5.  Draw  out  a  quarter  partition,  15  ft.  long,  going  through  two 
storeys,  supported  only  at  the  ends  of  the  lowest  sill,  and  carrying 
two  floors.  The  lowest  storey  is  11  ft.  6  in.  in  the  clear,  the  upper 
one  9  ft.  in  the  clear.  There  is  an  opening  9  ft.  by  9  ft.  in  the 
lower  storey,  and  there  are  two  doorways,  each  3  ft.  3  in.  by  7  ft. 
in  the  upper  storey.     (C.  and  G.  Hon.,  1902.) 

6.  Give  elevation  to  scale  J  in.  to  a  foot  of  a  quarter  partition 
18  ft.  wide  and  24  ft.  high,  running  through  two  storeys  and  self- 
supporting  over  the  ground  floor.  On  the  first  floor  is  a  central 
doorway  6  ft.  6  in.  wide  by  7  ft.  6  in.  high  ;  on  the  second  floor  is  a 
doorway  3  ft.  wide  and  6  ft.  6  in.  high,  3  ft.  6  in.  from  one  side- 
wall  ;  and  another  4  ft.  wide  and  6  ft.  6  in.  high,  2  ft.  from  the 
other  wall.  Give  details  of  joints,  show  all  ironwork  and  figure 
scantlings.     (C.  and  G.  Hon.,  1897.) 

7.  A  temporary  wooden  building  for  a  flower  show  is  to  occupy  a 
space  40  ft.  by  50  ft.  It  is  to  be  roofed  cheaply  in  one  or  two 
spans,  chiefly  using  deals  and  battens,  and  covering  the  roof 
^ith  felt.  Draw  a  cross-section  of  the  building,  and  part  of  a 
longitudinal  one,  with  details.  Scale  not  less  than  ^  in.  to  a  foot. 
(C.  andG.  Hon.,  1903.) 

8.  A  drill-shed,  40  ft.  wide,  is  to  be  constructed  in  an  extremely 
exposed  situation,  entirely  of  wood,  the  roof  being  slated.  Draw 
the  elevation  of  one  end,  the  cross-section  and  the  elevation  of  one 
bay,  to  not  less  than  J  in.  scale,  showing  how  you  would  protect  the 
shed  from  wind ;  height  to  wall  plate,  10  ft.  Accompany  the 
drawing  with  a  written  description.     (C.  and  G.  Hon.,  1902.) 


M.aj.  S 


CHAPTER  XI. 


MISCELLANEOUS  CAEl'ENTBY  CONSTRUCTIONS. 

SCATFOLDma. 

Scaffolds  are  temporarj  structures  of  wood,  which  serve  as 
platforms  upon  which  the  workmen  stand  during  the  execution  of 
any  worli  which  cannot  be  reached 
from  the  ground.  Scaffolding  is 
indispensable  not  only  during 
the  actual  erection  of  buildings, 
bridges,    etc.,    and    during    the 


construction  of  ships,  but  also  for  the  subsequent  work  of  the 
engineer,   painter,   etc.       The  extent   to   which   scaffolding    ia 


SCAFFOLDING. 


275 


required,  and  the  method  of  constructing  it,  vary  according 
to  the  use  to  which  it  is  to  be  put :  that  is,  whether  it  is  to  be 
used  for  supporting  the  workman  only,  or  for  carrying  also 
large  quantities  of  material. 

Trestles. — For  scaffolds  of  small  height,  wooden  trestles  of  the 
shape  shown  in  Fig.  525  are  much  used.  They  vary  in  height  up 
to  10' ;  the  larger  ones  are  very  clumsy,  however,  and  are  not  in 
general  use.  Fig.  526  shows  a  folding  trestle,  which  is  much 
employed  by  painters. 

Ladders. — Ladders  are  necessary    ^^  ^^ 

for  mounting  the  scaffolds.      The    lll^l Til 

sides  of  a  ladder  are  usually  made 


Fio.  627.— Throe  Rungs  of  a  Ladder.  Fio.  628.— Four  Rungs  of  a  Ijadder. 

by  cutting  a  larch,  or  spruce-fir,  pole  down  the  middle.  The 
pole  must  be  free  from  knots,  shakes,  and  other  defects,  and 
while  being  straight,  must  not  be  too  thick.  Its  thickness  is 
determined  by  the  length  of  the  ladder  required.  It  is  possible 
to  get  a  suitable  pole  from  40'  to  50'  long,  the  butt  end  of  which 
is  about  5"  in  diameter,  and  the  top  end  2V'  in  diameter.  The 
ladder  rungs  or  staves  are  of  hard  wood,  preferably  oak.  They 
should  be  riven  (i.e.  split),  rather  than  sawn,  to  the  required  size ; 
as  sawn  rungs  are  not  infrequently  cross-grained,  and  therefore 
untrustworthy.  The  rungs  are  placed  at  9"  distances  •,  they 
vary  la  length,  being  about  16"  long  at  thelo'weT  etv^,  ?wtt!\Y3f 


276      A  MAITOAt  OV  CAKPKNTRT  AND  JOINERY. 

at  tlie  upper  end  of  tlie  laddei' ;    they  are  circular  in  eection,  I 

being  thinner  at  the  ends,  and  the  aides  r>f  the  ladder  are  bored  1 

to   receive   thetn,  the  ends  of  the  i-ud^   being  seuui-ed  with  I 
paint  and  wedges. 


To  strengthen  the  laddei   still  more    small  bars  of  wrought 

iron,  placed  at  intervals  of  six  or  eight  rungs   are  passed  fiom 

side  to  Bide  juHt  under  the  rungs  and  the  elide  are  riveted  over 

I  waahers  (Fig   b2  )      For  access  to  high  scatToldin^    it  is 

stroagi/ adviBailile  to  use  short  \addci«-w\tfe(vei\\reR<,Undiinra, 


SeAJTOLWNG. 


W7 


rather  than  to  employ  long  ladders,  aa  the  fatigue  of  constantly 
cari'ying  up  materials  is  thereby  much  leKsenad.  In  the  con- 
struction of  large  buildingB,  indinsd  gangways  are  often  used 
instead  of  ladders.  When  such  gangways  are  more  than  one 
ptank  in  width,  the  planks  composing  them  are  fastened  together 
by  cross  ledges  nailed  to  the  nnder-sides. 

Bricklayers'  Scaffold.— In  the  erection  of  buildings  tlie 
builder  requires  an  elevated  scaffold  directly  the  work  of  build- 
ing becomes  too  high  to  be  reached  from  the  ground.  In  work 
of  BUiall  extent,  the  scalTold  may  simply  consist  of  scailbid 
boarda  resting  either  upon  trestles,  or  upon  cross-bearers 
(putlogs)  which  are  supported  by  short  uprights 
(standards). 

For  larger  buildings,  scaffold-poles  lashed  together 
are  almost  invariably  used  in  the  construction  of  the 
scaffold.  A  BCaflbid  of  this  description  used  for 
bi'icklayers'  work  ia  from  3'  to  4'  wide.  As  illus- 
trated in  Fig.  B39,  its  main  supports  are  vertioil 
Btandards  placed  about  6'  apart.  The  lower  eads 
of  the  standards  ai'e  either  lut  into  the  ground  for 
a  short  distance,  or  they  ai'e  placed  into  baiTela 
without  ends  which  rest  upon  large  slabs  of  stone, 
the  barrels  being  tilled  with  earth.  In  either  case  the 
earth  is  well  r.imnied  around  the  lower  ends  of  tlie 
jiosts  to  keep  them  in  position.  Across  the  standards, 
hniizoDtot  poles  called  leil^GrB  are  placed  at  suc- 
cessive heights  of  about  6' — that  ia,  at  the  height  ""■""■ 
of  each  tier  requiring  a  platform  for  the  execution  of  the  work. 
As  scaffolding  is  of  a  teniporiiry  character,  the  various  members 
iire  secured  together  with  either  hempen  or  steel  cords  lashed 
round  the  joinings.  The  cords  are  further  tightened  by  the 
inaeition  of  wedges  (Fig.  530)  between  them.  Besting  with  one 
end  upon  the  ledgers,  and  with  the  other  end  upon  the  wall,  are 
putlogs, — short  pieces  of  timber  (prefemhly  of  hard  wood)  about 
3"  thick,  and  from  3°  to  5"  wide.  The  putlogs  are  placed  about 
4'  apart,  and  carry  the  acaffSW  baams  which  form  the  platform. 
It  will  be  seen  that  the  putlogs  can  only  be  placed  in  position  as 
tbe  work  proceeds,  whereas  the  same  scaffold-boards  are  raised 
na  required.  The  putlogs  of  each  tier  of  scaffolding  are  left  in 
position,  with  scaffold  boards  here  and  there,  as  an  aid  in. 
g  tiie  ■ottffold  and  holding  it  to  the  'wsiH^    '^« 


278       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

boards  are  from  1^"  to  3"  thick,  and  should  by  preference  be  all 
the  same  length,  and  abut  end  to  end,  although  they  are  often 
laid  to  overlap  at  the  ends.  Along  the  outer  edges  of  the  plat- 
form, vertical  gruard  boards — 9"  to  12"  deep — should  be  fixed,  to 
prevent  any  material  from  falling  off  the  platform.  It  is  a  wise 
precaution  to  fix  also  a  gruard  rail — especially  when  a  scaffold  is 
very  high — at  a  height  of  about  3'  6"  above  the  platform  level. 
To  give  the  necessary  rigidity  to  the  scaffold,  and  prevent  any 
rocking  or  giving  way,  diagonal  braces  are  lashed  to  the  standards 
and  to  the  ledgers. 

If  the  height  of  the  building  is  so  great  that  standards  cannot 
be  obtained  long  enough  to  reach  to  the  top,  additional  poles 
may  be  lashed  to  the  upper  ends  of  the  lower  standards.  If  the 
height  of  the  scaffold  is  considerable,  or  if  it  has  to  carry  heavy 
weights,  each  standard  may  consist  of  two  parallel  series  of  poles 
lashed  together  with  the  joints  of  one  series  alternating  with 
those  of  the  other.  Hempen  cords  are  affected  by  the  weather, 
and  may  in  time  become  slack.  It  is  therefore  necessary  to 
examine  the  lashings  periodically. 

Masons'  Scaffold. — In  stone  buildings,  especially  those  in 
which  the  walls  are  built  of  large  stones,  the  scaffold  is  often 
constructed  so  that  it  is  entirely  separate  from  the  building. 
This  necessitates  two  separate  frames  of  standards  and  ledgers, 
so  that  both  ends  of  the  putlogs  are  supported  independently  of 
the  wall.  The  inner  row  of  standards  is  fixed  a  few  inches  from 
the  building  line,  to  enable  the  stones  to  be  put  in  position.  As 
there  is  no  tiie  to  the  wall  in  this  scaffold,  it  is  necessary  to 
brace  it  in  the  direction  of  the  width  of  the  platform. 

With  the  exception  of  the  differences  mentioned  above,  the 
arrangement  is  similar  to  the  bricklayers'  scaffold.  As  the 
building  material  used  by  the  mason  is  generally  heavier 
than  that  used  by  the  bricklayer,  however,  the  scaffold  is 
usually  made  stronger  by  placing  the  standards  and  the 
putlogs  nearer  together,  and  by  bracing  the  structure  more 
firmly. 

Gantries. — In  large  towns  or  in  places  where  there  is  con- 
siderable street  traffic,  and  a  building  is  erected  close  to  the 
footpath,  limits  of  space  render  it  advisable  to  ei'ect,  over  the 
footpath,  an  elevated  platform  called  a  gantry.  It  consists  of 
heavy  framewoiks  of  timber  arranged  in  two  parallel  rows,  one 
at  the  curb  of  the  footpath,  and  the  other  near  the  building  ; 


°"""°-^.T,.,ak,o, 


280       A  MANUAL  OF  CARPENTRT  AND  JOINERY. 

these  carry  joiats  which  support  a  sheeting  of  planks  at  a  height 
of  from  9'  to  13'.  Tlie  length  of  Buch  a  gantry  depends  upon  the 
character  of  the  work,  as  well  as  upon  many  other  conditions. 
In  the  construction  of  a  gantry  of  this  description  the  main 
timbers  are  usually  of  large  section,  and  the  joints  are  made  as 
simple  as  possible.  The  cleat,  iron  dog,  bolts,  and  coach  screws 
are  the  chief  means  of  fastening  the  timbers  together.  A  heavy 
wooden  curb  is  necessary  at  the  out«r  side  of  the  gantry,  to 


protect  it  from  the  street  traffic.     Fig.  531  shows  a  sketch  of 
such  a  gantry. 

The  heavy  timber  structures  which  support  the  travelling 
cranes  found  in  engineering  works,  in  timber  and  stone  yards, 
and  wherever  heavy  weights  have  constantly  to  be  carried  from 
one  place  to  another,  are  also  named  gantries.  Fig.  532  shows 
the  general  construction  of  such  a  ganti'y  with  the  supporting 
posts  fixed  in  the  ground.  An  altei'native  arrangement  to  that 
of  fixing  the  posts  into  the  ground  is  to  have  them  resting  upon 
heavy  wooden  curbs.  The  sixe  of  the  timbers  used  depends 
upon  the  span  of  the  traveller,  and  upon  the  weight  to  be  lifted. 


SCAFFOLDING.  281 

The  main  point  for  consideration  is  that  tlie  joints  niiiet  have 
good  abutments,  and  be  proiwriy  braced  and  stayed  in  order  to 
obtain  a  rigid  structure. 

Derrick  Towers. —Yel^  another  type  of  Bcaffold  i-*  requned 
io  the  erection  of  large  buildings,  namely,  that  to  (ariy  an 
elevated    jib   crane 

fixed    at    an    altitude  ifffl  r*] 

sufiiciently  great  to 
raise  the  various  build- 
ing materials  to  their 
respective  positions. 
The  platform  m  sup- 
ported by  3  or  4  framed 
timber  structures 
braced  together  in  the 
manner  shown  in  Figs. 
533  and  534,  and  called 
HeiTick  towers.  The 
size  and  material  of 
suoh  towers  depend  on 
the  height  of  the  plat- 
form and  the  weights 
to  be  raised.  The 
towers  usually  vary 
from  3'  to  8'  square. 

In  this  type  of 
scaffold  there  are 
generally    three    sup- 


Bhof 


1  the  1 


gram  sketch  (Fig.  533). 
One  of  the  lowers  {B) 
i  directly  beneath  the  u 


r  upright  of  the  jib 


other  two  support  the  ends  of  the  stays  of  the  crane.  The 
stays  are  usually  anchored  by  means  of  chains  or  wire  ropes 
down  the  middle  of  the  towers,  the  bases  at  A  being  loaded 
with  stones,  briclis,  or  other  heavy  material.  The  tower 
supporting  the  mast  of  the  crane  is  strengthened  by  an  addi- 
tional central  post. 


A  MANUAL  OP  CARPENTRY  AND  JOINERY. 


TIMBEBIHa  FOB  EXOAVATIONS. 

When  excavating  deep  trenches  in  soft  ground,  or  construct- 
ing the  puddle  treneliea  for  a  reservoir,  it  is  necessary  to 
support  (shore)  the  Bides  of  the  ti'enches  to  prevent  them  from 
giving  way. 

Timber  is  commonly  employed  to  keep  up  the  sidea  of  the 
earth  in  excavations,  and  generally  when  the  ground  is  such 
that  it  will  not  stand  without  support.    Timber  is  also  used 


to  provide  a  temporary  partition  and  to  divert  the  water, 
where  it  is  necesatry  to  alter,  repair,  or  reconstruct  the  banks 
of  rivers,  docks,  waterways,  et<;. 

limbeting  or  Shoring  of  Trenchea.— The  extent  to  which 
the  timbering  of  trenches  is  necessary  depends  upon  the  nature 
of  the  earth  which  is  being  dug  into,  the  depth  to  which  the 
trench  is  carried,  and  the  length  of  time  the  trench  ia  left 

With  ground  of  a  hard  nature,  and  a  depth  of  trench  not 
exceeding  5  feet,  it  is  often  sufficient  to  place  short  vertical  planks 
T"  to  9"  wide  and  2"  to  3"  thick,  called  poltng'  boards,  at  distances 
of  from  3  to  6  feet  apart,  with  horizontal  itruts  spanning  the 
width  of  the  trench  ajid  fixed  between  them  as  shown  in  Fig. 
S35,     The  size  of  the  struts  depends  upon  the  width  of  the 


TIMBERING  FOR  EXCAVA'ITONS.  383 

trench  ;  they  are  usually  either  square  or  rouud  in  section,  and 
from  4"  to  7"  side  or  diameter. 

An  alternative  method,  applicable  when  the  ground  is  loose, 
is  shown  in  Fig.  536.  It  consists  of  fixing  on  each  side  of 
the  trench  a  horizontal  shAetlutc  of  planks  from  13  to  14  feet 
long,  close  together,  and  held  in  position  by  vertical  waling 
plecm  and  horizontal  struts.  The  waling  pieces  are  placed  from 
3  to  5  feet  apart,  wiUi  the  sides  of  the  trench  cut  with  a  slight 
"  batter"  (slope) ;  and  the  struts  are  tightly  driven  between 


the  waling  pieces.  The  sheeliug  is  inserted  in  about  3  feet 
depths  {i.e.  four  sheeting  boards),  and,  as  the  depth  of  the 
trench  increases,  additional  sheeting  and  supports  are  fixed  in 
position. 

Another  method  of  timbering  or  shoring  up  the  sides  of 
a  trench  is  to  have  vertical  poling  boards  fixed  behind 
horizontal  waling  pieces,  which  are  held  in  position  by  horizontal 
struts  spanning  the  ti'ench  (Fig.  TiST).  If  the  ground  is  vei  y  bad, 
the  poling  boards  are  placed  close  together,  and  it  is  sometimes 
necessary  to  have  the  lower  ends  cut  so  that  the  poling  boards 
can  bo  driven  into  position  behind  the  waliag  ^ieuea  aa  VW. 


284      A  MANUAL  OP  CARPENTRY  AND  JOINERY. 


I  proceeds.  When  euuh  a  method  of  timbering  is 
adopted,  the  poling  boarda  are  from  6  to  8  feet  long;  and  as 
the  depth  of  the  trench  increases,  another  layer  of  polii^ 
boards,  with  waling  pieces  and  struts,  is  driven  in  front  of  and 
below  those  previously  driven. 

Figs.  535  to  537  illustrate  typical  examples  of  the  shoring  of 
trenches  under  ordinary  oonditions.  It  often  happens  that 
trenches  have  to  be  dug  to  a  considerable  depth  in  Btreeto 
whei'e  there  is  a  large  amount  of  heavy  traffic,  or  where  large 


buildings  abut  against  the  street.  It  in  not  uncommon  in  such 
cases  tti  have  fii'st  of  all  to  shore  up  the  buildings  on  each  sido 
of  a  street,  and  also  to  use  heavy  stmts  to  prevent  the  sides 
of  the  trench  from  giving  way  duriiif;  the  excavations. 

With  such  trenches,  platforms  resting  upon  the  struts  are 
necessary  to  allow  the  excavated  earth  to  be  thrown  out :  for  a 
workman  cannot  easily  shovel  earth  higher  than  6  feet. 

Tlie.  sides  of  very  deep  and  extensive  tienches  such  as  the 
puddle  trenches  of  reservoii's,  etc.,  are  supjwrted  usually  by 
horizontal  sheeting,  vertical  poling  boards,  and  struts.  All 
tbeae   timbers  are    much  strongei'  than  those    used  for  the 


TIMBERING  FOR  EXCAVATIONS. 


285 


narrower  trenches,  and  the  struts  are  braced  together  to 
prevent  any  giving  way  through  unequal  pressure. 

The  Timbering  of  Excavations.— If  the  earth  forming  the 
sides  of  deep  excavations  is  fairly  hard  and  compact,  it  may  be 
temporarily  supported  by  upright  poling  boards,  held  in 
position  by  either  inclined  or  hori- 
zontal struts.  If,  on  the  other  hand, 
the  ground  is  such  that  it  necessitates 
close  sheeting,  it  may  be  necessary 
to  drive  stout  gJiiAe  piles  into  the 
ground  at  about  10  feet  apart,  to  bolt 
to  these  horizontal  waling  pieces 
arranged  in  pairs,  and  between  the 
waling  pieces  to  insert  sheet  piling  of 
planks  driven  close  together.  If 
the  depth  of  excavation  is  consider- 
able, the  guide  piles  will  require 
bracing  or  stiffening  with  struts. 

Piling. — During  the  repair  or 
reconstruction  of  waterway  em- 
bankments, dock  walls,  river  walls, 
promenades,  etc.,  timbering  is  almost 
indispensable.  As  the  object  of  the 
timbering  is  to  provide  a  temporary 
partition  which  will  divert  the  water 
and  keep  the  scene  of  operations 
clear,  it  is  necessary  to  arrange  the 
timbers  so  that  the  partition  will 
be  practically  water-tight. 

One  way  in  which  this  can  be 
accomplished  is  to  drive,  into  the 
bed  of  the  river,  guide  piles  of  wood, 
shod  at  the  foot  with  iron,  and  each 

having  at  the  upper  end  an  iron  hoop  (Fig.  538)  to  prevent  it 
from  splitting  when  being  driven.  These  piles  are  placed  in 
an  upright  position,  from  8  to  12  feet  apart,  and  are  driven 
into  position  by  means  of  a  pile  driver  ;  and  waling  pieces 
arranged  in  pairs  are  then  bolted  to  them,  the  space  between 
the  waling  pieces  being  such  that  it  allows  of  planks  (sheet 
piles)  being  driven  close  together  between  them  to  fill  u|j 
the  space  between  the  guide  piles.     The  edges  oi  VXie  ^\a.T^^ 


Iron  Shoe 


Fio.  588.— Sketch  of  uppei*  and 
lower  ends  of  a  Wooden  Pile. 


286       A   MANUAL  OF  CARPENTRY  AND  JOINERY. 


forming  the  sheet  piles  are  often  either  grooved  and  toDgned 
(Fig.  540)  or  V-jointed  (Fig.  541) ;  and  the  lower  ends  ot  the* 


F10.ML 
TypOB  of  Joint  tor  Shset  Pilirs. 

LSh«  I 

Fta.  690.— Sheet  PUing. 

piles  are  cut,  as  sliown  in  Fig.  S39,  ao  that  as  they  are  driven 
they  tend  to  close  the  jointa  between  the  piles.  By  this  means 
a  temporary  partition,  or  coffer-dun  (Fig.  542^  is  formed  which, 


with  the  aid  of  a  pump,  effectually  excludes  the  water  from  the 
enclosed  apace.  If  the  work  ia  of  lai^  extent,  or  if  the  depth 
of  water  is  considerable,  the  guide  piles  require  stiffening  by 
struts  and  braces. 


SHORING  OF  BUILDINGS.  287 

A  more  effective  way  of  making  such  partitions  water  proof 
is  to  arrange  two  rows  of  piles,  about  18"  apart,  and  then  fill 
the  space  between  them  with  clay  puddle. 

Piles  similar  to  that  shown  in  Fig.  538  are  also  much  used  in 
the  foundations  of  large  buildings,  on  sites  where  a  layer  of 
soft  earth  overlies  firm  ground  but  is  too  deep  to  excavate. 
Such  piles  are  driven  from  3  to  4  feet  apart,  and  support  cross 
timbers  which  are  embedded  in  concrete.  Elm  is  the  best 
timber  for  piles  which  are  to  be  left  in  position  permanently. 


SnOBING  OF  BUILDINGS. 

Necessity  for  Shoring. — Whenever  a  building  shows  signs 
of  giving  way,  either  through  the  failure  of  the  foundations  or 
from  any  other  cause,  it  is  necessary  to  support  temporarily 
any  bulged  part  with  props  of  timber.  These  supports  are 
called  shores,  and  the  method  of  arranging  '  them  is  called 
shoring.  Shoring  is  also  required  when  structural  alterations 
necessitate  the  taking  down  of  some  portion  of  a  building, 
especially  if  parts  on  each  side  are  to  be  left  standing. 

The  shores  of  buildings  may  be  divided  into  three  different 
types : 

(1)  When  shoring  is  required  to  keep  up  the  corner  or  the 
sidos  of  a  building,  inclined  timbers  called  raking  shores  are 
placed  to  reach  from  the  ground  to  the  part  of  the  building 
which  requires  supporting. 

(2)  Horizontal  timbers  (flyini:  shoree)  and  inclined  struts  are 
inserted  between  two  buildings  during  the  reconstruction  of 
a  building  between  them ;  these  are  also  used  when  deep 
sewer  trenches  are  being  dug  in  narrow  streets  between  large 
buildings. 

(3)  Vertical  posts  called  dead  shores,  carrying  crossbeams 
(needles)  are  used  for  supporting  the  upper  part  of  a  building 
when  it  is  necessary  to  remove  the  lower  part  entirely. 

Precautions  to  be  adopted  when  Shoring.— The  shoring 
of  buildings  needs  great  care  and  calls  for  special  judgment. 
Any  careless  or  insecure  shoring  may  do  more  harm  than  good ; 
in  fact  it  may  be  fraught  with  great  danger  and  possibly  lo^s 
of  life. 

The  timber  for  shoring  must  be  sound  and  a\*YOii^  eviOM^ 


288      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

to  bear  the  stress  put  upon  it.  Since  the  work  is  temporary, 
and  the  material  can  afterwards  be  used  for  other  purposes,  it 
is  usual  to  employ  timbers  of  size  and  strength  greater  than  are 
theoretically  necessary.  It  should  be  noted,  also,  that  the 
shores  are  in  compression,  and  any  weakness  will  give  rise  to 
buckling ;  this  tendency  is  best  resisted  by  having  timbers  of 
square  cross-section.  Pitch-pine,  owing  to  its  being  obtainable 
in  long  straight-grained  lengths  and  free  from  large  knots, 
is  a  very  suitable  wood  for  shoring.  Care  must  be  taken  to 
examine  the  ground  upon  which  the  lower  ends  of  the  inclined 
or  dead  shores  rest,  to  see  that  it  is  solid,  free  from  old  drains, 
and  capable  of  withstanding  the  pressure  to  be  placed  upon  it. 
*A11  shores  should  be  put  in  position  with  a  minimum  of  knock- 
ing, which  of  necessity  causes  vibration.  As  they  are  generally 
used  to  prevent  any  further  giving  way,  rather  than  as  a  means 
of  forcing  back  any  defective  part,  care  should  be  taken  not  to 
overstress  the  wall  in  fixing  the  shores  in  position. 

Baking  Shores. — The  best  angle  for  raking  shores  is  45 
degrees.  Space  will  seldom  allow  of  shores  being  fixed  at  this 
angle  ;  a  more  usual  one  for  the  top  (longest)  shore  is  from  60  to 
70  degrees  with  the  horizontal. 

The  lower  ends  of  raking  shores  should  rest  upon  a  sole-piece 
or  small  platform  of  timber,  to  distribute  the  pressure  over  the 
ground  surface.  This  sole-piece  often  consists  of  two  or  thr®® 
thicknesses  of  planks  crossing  each  other  at  right  angles.  The 
lower  ends  of  raking  shores  should  have  a  small  notch  cut  into 
them,  to  enable  a  crowbar  to  be  used  in  tightening  them  i^ 
position. 

At  the  upper  ends,  a  vertical  wall  piece — a  plank  about  11"  ^y 
3" — is  fixed  against  the  wall ;  and  needles — pieces  of  tinil>®^ 
about  18"  long  by  4"  square — pass  through  holes  made  in  tb© 
wall  piece,  go  into  the  wall  for  a  distance  of  from  4"  to  8",  ai*^ 
project  outside  the  wall  piece,  thus  providing  an  abutment  ^^' 
the  upper  ends  of  the  raking  shores.  The  point  of  abutm^^ 
should  be  a  little  below  the  floor  level,  the  floor  thus  providi^^ 
the  necessary  reaction.  The  needle  is  further  strengthened  ^- 
placing  above  it  a  cleat  which  may,  with  advantage,  be  hou^^* 
into  the  wall  piece  for  about  half-an-inch.  Fig.  ,543  show^ 
sketch  of  the  upper  end  of  a  raking  shore  in  position,  abuttii^ 
against  a  needle.  The  part  of  the  needle  which  goes  into  t>^ 
Wdll  is  usually  cut  so  that  it  ftta  into  a  hole  made  by  removi 


SHORING  OF  BUILDINGS. 


Fig.  MS, -Sketch  ol  iiiipcr  and  Inwct  onda  o(  ■  Baiting  Shore. 


290      A  MANUAL  OF  CABPENTRY  AND  JOINERY. 

half  a  brick.  It  will  be  noticed  that  the  upper  end  of  tbe 
raking  shore  is  hridled  on  to  the  needle  to  prevent  it  from 
getting  out  of  position. 

When  a  number  of  raking  shoi'es  are  in  the  same  vertical 
plane,  aa,  for  example,  in  a  building  several  storeys  high  (Fig. 
544),  the  lower  ends  nsually  all  rest  upon  the  same  sole  piece, 
and  may  be  fastened  to  it  with 
iifln  dogs.     The  lower  ends  may 
be  placed  close  to  each  other,  oi 
there  may  be  a  space  of  from  & 
to  8"  left  between  them  to  allo'^ 
of  either  tightening  a  single  shor**) 
or  removing  it  without  diaturbiE^g 
tlie  others.      It  is  an   advanta.^^ 
to  have  the  wall  pieces  as  loiK^S 
aa  poaaible,  and,  if  practicable,       ^* 
have  the  upper  ends  of  all  t>1i* 
leaking  ahores  in  the  same  pla—  t* 
abutting   against   the   aanie  w  ^bM 
piece,    with   a  needle   going   ic  -»^ 
the  wall  at  the  upper  end  of  ei^"-*' 
shore.    With  high  buildings  it^^  '■ 
sometimes  convenient  to  have  ^fc^^'i' 
longest    shore    in    two    lengtt-^^^ 
the   lower   length    resting    up^^^"; 
the    shore    beneath   it— which  ' 

accordingly  arranged  to  be  a  lit:^-'' 
stronger.      The   upper  length 
this  top  sliorc  is  called  a 
and   the   shoiu   underneath   it  " 

called  the  back  eLore.     The  ri«^'er 
g^„^,  shoi'e   ia   tightened    by   insert-:^"!? 

folding  wedges  as  at  ^  (Fig.  5^^-^)- 
Raking  shores  are  stiffened  by  nailing  braces  consisting  "' 
boards  from  \"  to  2"  tliick  to  tbe  sides,  at  diffeient  heigt^-'^ 
aa  shown  in  Fig.  544.  When  several  raking  ahores  are  pla*::'™ 
with  their  lowei'  ends  close  together,  stout  hoop-iron  is  ot*^  ^" 
nailed  round  them  with  clout  nails  to  bind  them  together- 
Flying  Shores. — Fig.  G45  shows  an  example  of  the 
flying  ahores.  These  consist  of  horizontal  timbers  plac? 
between   two   buildings   when   it   is   necessary    to   remove 


SHORING  OF  BUILDINGS. 


291 


reconstruct  a  building  between  them.  They  are  also  occasionally 
placed  across  a  narrow  street,  from  building  to  building,  during 
the  excavation  of  a  deep  trench  for  a  sewer.  Flying  shores  are 
better  than  raking  shores,  where  they  can  be  adopted,  as  they 
act  more  nearly  at  right  angles  to  the  pressure.  Wall  pieces 
are  first  fixed  in  position,  with  needles  running  through  them 
and  into  the  wall  at  the  required  heights  for  support.  It  is 
usual  to  have  struts  meeting  on  each  side  of  the  horizontal 
^flying)  shore,  and  to  have  a  straining  piece  between  the  struts. 


Fio.  545.  Pio.  546. 

Methods  of  arranging  Flying  Shores. 

The  whole  system  is  tightened  when  in  position  by  inserting  fold- 
ing wedges.  Figs.  545  and  546  show  two  different  ways  of 
arranging  flying  shores.  If  the  struts  are  long  they  may  be 
stiffened  by  nailing  braces  across  them,  as  with  raking  shores. 

Dead  Shores  are  the  vertical  posts  used  to  support  needle 
Bhores  when  it  is  necessary  to  underpin  a  building  to  renew  the 
foundation,  or  when  the  lower  part  of  the  front  of  a  building  is 
taken  out,  as,  for  example,  during  the  conversion  of  a  house 
into  a  shop  with  a  large  window  opening  (Fig.  547). 

In  this  kind  of  shoring  it  is  necessary  to  get  the  posts  as 
tkearly  as  possible  underneath  the  structure  they  have  to 
Support.  This  plan  shortens  the  bearing  length  of  the  needles, 
^nd  consequently  increases  their  strength.  The  outer  posts 
should  rest  upon  sleepers  in  order  to  distribute  tYie  >Nei\^\.  ON«t 


292       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

a  larger  surface  of  the  ground.    The  inaer  poata  should  al 


^m 


nDog 


have  a  firm  base  ;  if  the  building  has  a  basement  it  will  be 
necessary  either  to  pierce  the  floor  or  to  fix  posts  from  the  floor 
in  the  basement  directly 
underneath  those  required 
to  support  the  needles.  By 
this  means  a  direct  bearing 
from  the  ground  is  ob- 
Oead  Shore     tained. 

When  fixing  shoring  of 
this  description,  it  is  first 
necessary  to  make  holes 
through  the  wall  above  the 
level  at  which  the  girder 
has  to  be  inserted.  These 
boles  are  placed  in  the  best 
position  for  carrying  the 
weight  above,  the  needles 
are  passed  through  them, 
and  the  dead  shores  are 
fixed  in  position,  being 
tightened  by  means  of  told- 
mg    Nted^^ea,      When     the 


Fio.  S4a.—Detal]  ol  Dead  8h< 


^^^^&: 


SHORING    OF   BUILDINGS.  2d3 

weight  is  considerable,  or  when  the"  needles  cannot  be  supported 
at  points  nearly  under  the  walls,  and  have  consequently  to  be 
long,  diagonal  struts  may  be  used,  or  the  needles  may  be  of 
wrought  iron  or  steel.  It  is  a  wise  precaution  to  brace  the  dead 
shores  in  a  diagonal  direction.  Baking  shores  are  often  also 
necessary  in  such  cases  to  keep  the  walls  vertical ;  this  is 
especially  so  at  the  corner  of  a  building. 

Whenever  shoring  is  necessary,  it  is  advisable  to  place  struts 
between  the  reveals  of  all  window  or  other  openings  in  the  walls, 
as  shown  in  Fig.  547. 

WOODEN  CENTRES. 

Whenever  arches  of  brick,  stone,  or  concrete  are  built,  as 
for  examples  in  the  heads  over  window  openings  or  doorways, 
in  bridge  construction,  in  groined  work  of  roofs,  etc.,  wooden 
structures  are  used  temporarily  for  supporting  the  parts  of  the 
arch  during  the  construction.  These  wooden  structures  are 
called  centres.  The  upper  surface  of  the  centre  corresponds  in 
outline  to  that  of  the  soffit^  that  is,  the  underside,  of  the  arch. 

Fixing  the  Centres. — All  centres  used  for  supporting  arches 
should  be  fixed  in  position  so  that  they  can  be  lowered  (eased) 
as  soon  as  the  construction  of  the  arch  is  completed,  and  thus 
allow  any  slight  irregularity  in  the  brickwork  to  adjust  itself 
before  the  mortar  sets. 

With  the  simpler  types  of  centre  this  is  provided  for  by 
r'esting  the  ends  upon  vertical  posts,  and  by  inserting  folding 
hedges  between  the  upper  ends  of  the  supporting  posts  and  the 
ends  of  the  centre.  As  soon  as  the  arch  is  completed,  these 
vrooden  wedges  are  slackened  and  the  centre  slightly  dropped, 
tx)  allow  the  arch  to  find  its  bearings.  Hardwood — preferably 
teak — should  be  used  for  the  wedges,  they  should  be  arranged 
either  in  pairs  or  three  together,  with  the  thin  ends  blunt  so 
that  they  can  be  driven  out  easily. 

With  very  large  or  complicated  centres,  special  consideration 
needs  to  be  given  to  the  means  of  easing  the  centres. 

Centres  for  Small  Arches.— A  centre,  or  turning  piece,  for 
a  flat,  or  segmental,  arch  of  not  more  than  six  feet  span  in  a 
half-brick-thick  or  a  thin  stone  wall  is  readily  constructed  by 
cutting  to  the  required  curvature  one  edge  of  a  plank  of  2" 
to  3"  in  thickness. 


294      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


An  alternative  method  of  constructing  such  a  centre  ia  illua- 
trated  in  Figs.  549  and  650.    It  consists  of  two  parallel  boards 


(ribs),  each  one  inch  thick  (Fig.  552,  a  and  b),  which  have  their 
upper  edges  cut  to  the  required  curvature,  and  are  conaected 
throughout  their  curved  length  by  narrow  wooden  stripe  (logs) 


for  supporting  the  bricks  of  the  aicli.  The  size  of  the  lags  is 
from  1"  to  2"  wide,  and  about  an  inch  thick  ;  and  they  are  placed 
about  J"  apart.  Their  length  jtnd  the  distance  apart  of  the 
two  ribs  to  which  they  aie  nailed  depend  upon  the  thickness 
of  the  wall.     The  length  of  each  lag  should  be  at  least  half  an 


WOODEN  CENTRES. 


295 


rC 


inch  less  than  the  thickness  of  the  wall,  so  that  the  bricklayers' 
"guide-line"  may  not  be  interfered  with.  The  ribs  are  con- 
nected on  the  underside  by  a  short  horizontal  tie  at  each  end  ; 
this  provides  a  seating  for  the  folding  wedges. 

Setting  out  the  Curve  for  a  Segmental  Arch.— In  obtain- 
ing the  curve  of  the  wooden  centre  for  a  segmental  arch,  it  is 
often  difficult  to  find  the  "strik- 
ing point,"  or  geometrical  centre, 
of  the  curve.     When  this  point  is 

inaccessible,  and    the    width    of    A 

the  opening  and  the  rise  of  the 
middle  of  the  arch  above  the 
springing  line  are  given,  a  practical  way  of  determining  the 
curve  is  as  follows  : — Drive  three  nails  a,  b,  c,  (Fig.  554)  into 
a  board  such  that  ab  is  the  span  and  cd  is  the  rise.  Obtain  two 
laths,  each  double  the  length  of  ac,  and  nail  them  together  so 
that  they  cross  each  other  at  c ;  let  the  outer  edges  of  the  laths 
rest  against  the  nails  a,  b,  c.  Connect  the  laths  by  a  third  lath 
so  that  the  angle  acb  will  be  fixed.    Now  remove  the  nail  c,  and 


B 


Fio.  658. 


Fio.  554. — Method  of  obtaining  tho  curved  outline  of  a  Wooden  Centre. 

substitute  the  pencil  for  it,  and  move  the  laths  so  that  their 
edges  remain  in  contact  with  a  and  b.  The  pencil  will  trace  the 
segmental  curve  required.^ 

The  method  of  calculating  the  radius  of  curvature  for  a  seg- 
mental arch,  when  the  width  of  opening  and  the  rise  in  the 
middle  are  given,  is  as  follows  : 

Square  half  the  width  of  the  opening,  divide  by  the  rise,  add 
the  rise,  and  divide  by  two,  all  in  the  same  units. 

Or  (Fig.  553),      radius  =  ^^  ^  ^     ^ d . 

^  Students  who  have  read  Euclid  will  recognise  that  the  method  depends 
upon  III.  34. 


296       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

Example. — An  arch  has  a  span  of  six  feet^  and  a  rise  of  8 
inches.     Find  the  radius  of  curvature. 

Half  the  ^idth  of  span =3  feet  =  36  inches  ; 

^.     ^(362-r8)+8^(1296-r8)  +  8^162  +  8 

=  ijo=85". 
.'.   Radius  of  curvature =85" =7'  1". 
Graphically,  the  question  resolves  itself  into  determining  the 
centre  of  a  circle  which  passes  through  three  given  points 
(p.  26). 

Centres  for  Larger  Arches. — The  centre  for  a  segmental, 
semi-circular,  or  semi-elliptical  arch,  suitable   for  spans  not 


rWedges. 

'  Upri9h^ 

Support 


Tre  consisting  of 
J  ^2  pieces. 


IE 


Fia.  555. 


Fio.  5r>6. 


1 ^ 

Fio.  557. 

Types  of  Wooden  Centres. 


Fig.  558. 


more  than  12  feet  wide,  may  have  each  of  the  curved  ribs  built 
up  of  two  thicknesses  of  one-inch  boards,  nailed  together  with 
overlapping  joints  so  that  the  joints  of  one  layer  are  in  the 
middle  of  the  length  of  the  boards  of  the  other  layer.  The 
lower  ends  are  kept  from  spreading  by  nailing  or  bolting  across, 
at  the  springing  level,  a  horizontal  tie,  6"  to  9"  wide  and 
J"  to  2"  thick.     The  curved  ribs  are  stiffened,  and  rigidity  is 


WOODEN  CENTRES. 


297 


ElevaMon 


Developmenf 


given  to  the  centre,  by  adding  braces  of  4"  or  5"  by  1  J",  as  shown 
in  elevation  in  Fig.  551.  If  the  wall  is  a  thin  one,  of  not  more 
than  half-a-brick,  or  6"  of  stone,  one  only  of  these  ribs  is 
required.  If  the  wall  is  thicker  than  this,  then  two  ribs, 
connected  on  their  curved  edges   by  lags,  are   required — the 

distance  apart  of  the  ribs  and  the   length  of  the  lags  being 

governed  by  the  thickness  of 

the  wall. 

An  alternative  method  of 

construction,  and  one  which 

is  applicable  to  openings  of 

not  more  than  20  feet  wide, 

is  to  make  the  centre  out  of 

thicker  stuff,  2"  to  4"  thick, 

"built  up  as  shown  in  eleva- 
tion in  Fig.  555.      The  ribs 

of  this   type   of  centre   may 

abut   end   to  end   and  have 

stump  tenons  on  the  ends  of 

the   struts  fitting  into   mor- 
tises  made    into    the   under 

side  of  the  ribs  (Fig.  556)  ;  or 

the  struts  may  be  arranged 

so  that  the  ends  go  between 

the  ribs  as  shown  in  Fig.  558. 
In  either  case  it  is  necessary 
to  secure  the  various  mem- 
hers  of  the  centre  together 
by  means  of  light  iron  dog^s 
as  shown  in  the  drawings 
(Figs.  555  and  557). 

Many  modifications  may  be  made  in  the  arrangement  of  the 
struts,  to  fulfil  the  requirements  when  the  centre  has  to  carry 
(i)  a  very  heavy,  or  (ii)  only  a  light  arch,  when  (iii)  the  centre 
is  to  be  supported  at  the  ends  only,  or  (iv)  intermediate 
supports  are  also  to  be  used.  Figs.  555  and  557  are  elevations 
of  typical  examples  of  wooden  centres. 

For  centres  used  for  supporting  large  bridges,  etc.,  the  framed 
ribs  are  built  up  to  the  required  curvature,  and  are  placed  at 
from  3  to  4  feet  apart,  with  a  sheeting  of  battens  or  boards  laid 
upon  them. 


Fio.  659.— Details  of  Centre  for  "  Circle- 
ou-circlc  "  Ai'ch. 


298       A   MANUAL  OF  CARPENTRY  AND  JOINERY. 

The  curves  of  archea  for  which  centres  are  required  7317 
wideljr.  They  uiay  be  segmental  (i.e.  area  of  circles)  Bemi- 
elHptical,  or  even  built  up  of  area 
of  circles  of  different  radii,  or  be 
com  posed  of  other  complex  curves 
which  cannot  be  considered  here- 
in geiiei'al  the  detenuiDation  of  the 
curve  ie  a  practical  application  "^ 
geometry. 

The    construction    of    centrea    fot 
"  circie-on-circle "     arches,    and    tw 
supporting    groined    arches,    presen' 
PiiLHa.— PnmsdStandlor     other     interesting     eiampleH    of    t^^ 
lu'PS™.*^"'*"  '^'*'  "*'    application  of  practical  geometry    W 
carpentry.    Fig.  559  shows  the  eleva- 
tion and  plan,  with  the  development  of  the  curvature  of  tb® 
ribs,  of  a  centre  tor  an  arch  which  is  semicircular  in  eleTatJow 

Eltvathin'of  RibA 


^"  Wooden  centres.  '^ 

and  aegmentul  in  plan.     Fig.  5G0  is  a  skel;c)i  (if  the  Hupportiug 
frame  for  such  a  eeiiti-e. 

Fig,  B61  showH  tbe  dataila  of  the  centres  inquired  where  four 

semi -circular  arches  of  equal  mdii,  and  at  right  angles  to  each 

other,  iDtereect  at  the  Baiue  height.     The  angle  rihs,  which  are 

built  up  of  two  thickneasea,  require  to  he  "backed"  (aa shown  in 

^^plan  in  Fig.  56!)  to  provide  a  eeatiug  for  the  aheetitig.    To  obtain 


^  Fid  ^3  — akotcli  of  Wnodon  ContreB  ahown  In  detail  in  Ftg.  Sfll. 

this  backing  it  is  necessary  to  have  a  template  of  the  required 
outline  of  the  angle  ribs,  and  to  slide  it  along  the  face  of  the 
centre  for  the  distance  shown  at  A'  and  B'  (Fig.  561),  Fig.  562  is 
a  sketch  of  the  centres  just  deBcribed,  with  part  of  the  sheeting 
omitted  to  show  the  general  arrangement. 


SPECTATORS'  STAin)S. 

For  the  purpose  of  witnessing  field  Hports,  cricket,  or  football 
matches,  sti'eet  procesxions,  etc.,  elevated  wooden  tlsrad  ataiLdi 
ai'e  much  iwed.  The  construction  of  these  varies  according  to 
whether  they  are  of  a  temporary  chamcter  only,  or  are  to  remain 
as  permanent  stnictiires.  Again,  perm  a  lien  t  apectatoii*'- 
Btands  are  often  entir^ely  or  paitly  enclosed,  in  which  case  they 
l>ecuiue  the  gallurifid  Hour  or  ficjors  of  a.  building  which  nia,y  be, 
aud  often  is,  erected  entirely  of  wood. 


300    A  Manual  of  carpentry  and  joinery. 

With  stands  of  a  teniporury  clmracter,  the  construction  ia 
usually  effected  out  of  tlii 


lI«iptQfflI|„ 

^  Na.  Jra  1                      i 

fitn^f^i^^i" 

I''       J,  ^'!P 

'Hitttytlait :  ml 

'iizes)  of  pUnks  and  dea,la  the  joints  being  made  is  simple  A-^ 
possible  with  an  extensive  u<ie  of  the  cleat  <ind  non  dog  as  ^ 
means  of  fastening  the  vatiu  i  puits  bigethei  M  ith  the  more 
pemjanent  BtnictaieK,accunkte  cAlcuUtions  maj  with  advantage 


SPECTATORS'  STANDS. 


301 


}  employed  to  obtain  the  requisite  sizes  of  the  timbers,  and 

le  whole  is  framed  together  more  rigidly. 

Spectators'  stands,  when  crowded  with  people  who  are  likely 

become  excited,  tend  to  swing,  and  therefore  special  care 
ould  be  devoted  to  the  bracing  together  of  such  structures  to 
)tain  rigidity.  Especially  when  the  stands  are  much  elevated, 
le  vertical  supports  should  be  strong  and  should  be  well  braced 

a  diagonal  direction,  so  that  there  is  no  possibility  of  giving 
ay.  The  posts  should  also  be  placed  upon  large  base  stones  or 
pon  concrete  blocks  so  that  the  lower  ends  are  clear  of  the 


m^^^im^^i 


SeaMhZ" 


Fio.  666. — Detailed  Section  of  Seats  of  Spectators'  Stand. 

imp  ground.  For  temporary  stands,  rough  sleepers  of  wood, 
concrete  piers  may  be  laid  for  the  timbers  to  rest  upon, 
'hen  the  stand  is  of  large  area  it  is  necessary  to  consider 
pecially  the  means  of  egress  in  case  of  panic.  To  attain  this 
►jeet  it  is  well  to  divide  up  the  stand,  by  handrails,  into 
Qgths  of  from  15  to  20  feet,  and  also  to  divide  into  two — 
T  a  handrail  up  the  middle — each  passage  which  gives  access  to 
e  upper  part  of  the  stand. 

The  accommodation  of  a  stand  depends  upon  whether  the 
:cupants  require  seating  accommodation,  or  standing  room 
ily.  This  consideration  also  influences  the  general  arrange- 
ent  of  the  timbers.  If  seats  are  to  be  provided,  the  space 
jquired  iov  each  person  is  from  18  to  20  inches. 


302       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

Figs.  563  to  565  show  plan  and  two  sections  of  a  temporary 
stand  constructed  out  of  deals  and  quartering,  with  the  main 
dimensions  given.  It  consists  of  ten  tiers  in  depth,  each  tier 
rising  8  inches  above  the  one  below  it.  The  length  of  such  a 
stand  and  also  the  number  of  tiers  composing  it  will  necessarily 
depend  upon  the  accommodation  required  or  upon  the  amount 


Fig.  5G7. — Detailed  Section  of  Seats  of  Spectators'  Stand. 


of  available  apace.  In  this  example  the  length  is  divided  into 
19  feet  distances,  the  approaches  to  the  di  He  rent  sections  are 
arranged  in  pairs,  with  a  stout  handrail  between  them,  and  a 
handrail  is  arranged  midway  between  the  lengths  of  the  seats. 
Allowing  for  the  thickness  of  this  handrail,  each  section  has  ten 
seats,  each  15  feet  10  inches  long,  which,  allowing  19  inches  for 
each  person,  provides  accommodation  for  100  spectators.  Fig. 
566  shows  an  enlarged  dimensioned  section  through  two  tiers 
of  this  stand. 


SPECTATORS'  STANDS.  303 

An  alternative  method  of  construction,  often  adopted  in  per- 
manent stands,  is  shown  in  section  in  Fig.  567.  It  consists  of 
joists  inclined  to  give  the  necessary  difference  in  height  of 
successive  tiers  (usually  from  6"  to  9"),  and  placed  at  from  15" 
to  18"  apart.  These  joists  are  supported  either  upon  heavy 
cross-beams  and  posts,  or  upon  steel  girders  and  cast-iron 
columns.  The  horizontal  surfaces  are  obtained  by  lining  up 
the  upper  edge  of  the  joists  with  3"  by  3"  quartering,  upon 
which  rest  floor  boards  from  1"  to  1^"  thick.  The  risers 
between  one  tier  and  the  next  are  also  boarded. 

The  seats  on  such  a  stand  are  placed  at  the  front  edge  of  each 
tier  ;  they  may  be  made  more  comfortable  by  fixing  a  back  rest 
behind  each  row  of  seats.  It  will  be  seen  that,  whereas  each 
tier  is  not  more  than  9  inches  high,  th,e  seat  will  require  to  be 
17  inches  high  ;  this  arrangement  will  allow  the  feet  of  those 
on  one  seat  to  rest  on  the  floor  without  interfering  with  the 
comfort  of  those  seated  in  front  of  them. 


Summary. 

Scaffold  boards  are  supported  by  trestles,  or  by  a  framework  of 
2)ole8  fastened  together  by  cords  and  wedges. 

A  masons'  scaffold  is  so  framed  as  to  be  independent  of  any 
support  from  the  building  itself,  while  one  end  of  each  pvUog  of  the 
bricklayers'  scaflbld  usually  rests  upon  the  wall  being  built. 

A  g^antry  is  an  elevated  platform  so  built  as  to  allow  traffic  to 
proceed  beneath  it.  The  heavy  timber  framing  used  to  carry  over- 
head travelling  cranes  is  also  called  a  gantry. 

Derrick  towers  are  framed  timber  structures  carrying  a  platform 
used  to  support  an  elevated  jib  crane. 

The  sides  of  excavations  for  sewers,  drains,  and  for  deep  founda- 
tions of  buildings  are  temporarily  supported  (shored)  by  struts, 
poling  hoards,  wcUing  pieces,  etc. 

Piles  are  heavy,  pointed  beams  driven  into  the  ground  either  to 
form  the  main  supports  of  the  partitions  used  as  water  coffer-dams, 
or  for  foundations  in  soft  earth. 

Shoring  is  the  arrangement  of  temporary  wooden  supports  (shores) 
for  parts  of  a  building  liable  to  give  way  during  structural  altera- 
tions. Shores  may  be  arranged  as  raking  shores,  flying  shores,  or 
dead  sJiores. 

Wooden  centres  are  frames  upon  which  brick  arches  are  supported 
during  construction. 


304      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

Spectators'  stands  may  be  temporary  or  permanent ;  the^  should 
be  well  braced  together.  For  temporary  stands  the  stock  sizes  of 
timber  are  used  with  simple  connecting  joints.  Permanent  stands 
are  of  more  elaborate  construction. 


Questions  on  Chapter  XL 

1.  Make  sketches  oi  two  types  of  scaffold  trestle,  and  also  of 
about  six  rungs  at  the  lower  end  of  a  ladder.  Dimension  the  sizes 
of  the  different  parts  of  the  ladder,  and  state  the  best  materials  for 
its  construction. 

2.  Draw,  to  a  scale  of  |  in.  to  one  foot,  the  elevation  and  a 
vertical  cross  section  of  the  bricklayers'  scaffold  required  in  the 
erection  of  a  wall  24  feet  long  and  24  feet  high.  Name  the  various 
parts. 

3.  Draw  a  cross  section  of  a  gantry  required  for  a  stone  buildingi 
which  is  to  be  built  close  against  a  public  foot-path  10  ft.  above 
pavement,  and  to  have  protecting  rail ;   also  draw  elevation  from 
roadway,  showing  rather  more  than  one  complete  bay,  the  uprights 
being  10  ft.  apart.     Scale  J  in.     (C.  and  G.  Hon.,  1904.) 

4.  Make    a    sketch    of    a    gantry    to    support    a    "traveller." 
Dimension  the  scantlings  used.     (C.  and  G.  Hon.,  1900.) 

5.  Draw,  to  a  scale  of  ^  in.  to  one  foot,  a  plan  and  a  vertical 
cross  section  of  a  sower  trench  in  l)ad  ground,  10  ft.  deep,  and  show 
all  the  timbering  required  to  keep  the  sides  intact.  Name  and 
dimension  all  the  parts. 

6.  One  of  the  banks  of  a  river,  the  average  depth  of  which  is  3  ft., 
having  shown  signs  of  giving  way  for  a  length  of  about  30  ft.,  it  is 
necessary  to  divert  the  course  of  the  water  to  enable  the  bank  to  be 
repaired.  Make  sketches  showing  the  timbering  required  for  the 
purpose. 

7.  Draw  a  raking  shore  against  a  dwelling-house  four  storeys 
high.  Figure  the  scantlings  of  the  different  timbers  and  give  their 
names,  and  describe  how  such  a  shore  is  fixed  in  position.  (C.  and 
(;.  Ord  ,  1903.) 

8.  Make  a  sketcli  of  the  upper  end  of  a  raking  shore  abutting 
against  a  brick  wall.     Name  and  dimension  the  different  parts. 

9.  Two  houses  of  18  ft.  frontage  each  in  a  terrace  have  been 
pulled  down,  and  shoring  is  required  for  supporting  the  adjoining 
houses  on  each  side.  Sketch  to  scale  ^  in.  to  a  foot  the  shoring 
you  would  construct,  and  give  detiiils  of  the  joints.  (C.  and  G. 
Hon.,  1897.) 


QUESTIONS  ON  CHAPTER  XI.  305 

10.  Two  buildings  are  each  three  storeys  high  and  15  ft.  6  in. 
apart.  Make  a  drawing  showing  how  these  buildings  would  \>e 
shored  with  flying  shores.     (C.  and  G.  Ord.,  1902.) 

11.  Describe  and  show  in  detail  the  mode  of  taking  out  the  front 
"wall  of  a  ground  storey  to  insert  a  shop  front,  with  needful 
shoring.     (C.  and  G.  Hon.,  1898.) 

12.  A  centre  is  required  for  a  segmental  arch  of  30  ft.  span  and 
10  ft.  rise.  Make  rather  more  than  half  elevation,  and  show  how 
you  would  provide  for  striking  such  a  centre.  (C.  and  G.  Ord., 
1903.) 

13.  Make  a  drawing  of  a  centre  to  carry  a  semicircular  brick  arch 
of  38  ft.  span.     (C.  and  G.  Ord.,  1902.) 

14.  A  centre  is  required  for  an  elliptical  arch  of  stonework, 
having  25  ft.  span  and  10  ft.  rise.  Draw  to  a  scale  of  |  in.  to  the 
foot  such  centering,  and  mark  thereon  scantlings  of  the  timbers. 
(C.  andG.  Hon.,  1898.) 

15.  (a)  Draw  a  centre  for  a  masonry  elliptical  arch,  20  ft.  span, 
to  be  carried  by  the  piers  that  will  support  the  arch.  Show  how 
the  centre  is  to  be  eased  and  struck. 

lOr], 
Sketch  and  describe,  in  writing,  a  gantry,  35  ft.  high,  to  carry  a 
steam  crane  for  use  on  a  large  building.     (C.  and  G.  Hon.,  1901.) 

16.  Make  an  elevation  and  section  of  the  centre  required  for  a 
pointed  arch  with  a  span  of  16  ft.,  and  with  apex  15  ft.  above 
springing,  which  is  12  ft.  above  the  ground.  The  arch  to  be  of 
stone,  with  flat  soffit  18  in.  wide.     (C.  and  G.  Hon.,  1904.) 

17.  Draw  to  a  scale  of  J  inch  to  a  foot  the  centering  for  two 
Semicircular  brick  arches  intersecting  at  right  angles  to  each  other, 
tihe  widths  of  arches  10  ft.  and  the  rise  5  ft.  Show  the  method  of 
cutting  the  boarding  accurately  at  the  groins.  (C.  and  G.  Hon. , 
1895. ) 

18.  A  staging  is  required  for  persons  to  sit  and  view  a  procession, 
the  front  of  the  staging  to  abut  on  the  street,  the  depth  of  the 
ground  is  20  ft.,  the  frontage  is  22  ft.,  no  support  to  the  staging 
can  be  obtained  at  either  end.  Make  plan  and  sections  in  pencil  to 
a  scale  of  i  in.  to  the  foot.     (C.  and  G.  Hon.,  1899.) 


jcax  u 


CHAPTER   XII. 
MECHANICS  OF  CABFENTBT. 

It  is  well  known  that  some  members  of  a  framed  structure 
must  be  made  stronger  than  others.     The  reason  is  that  tlie 
weights  or  other  forces  acting  on   a  truss  diflPer  from  each 
other  in  magnitude  and  direction.     It  is  obviously  necessary, 
therefore,  to  be  able  to  estimate  the  various  forces  acting,  so 
that  the  members  may  be  made  of  the  required  strength  with- 
out undue  waste  of  material.     The  general  principles  underlying 
the  measurement  of  forces  may  with  advantage  now  be  con- 
sidered briefly. 

The  Nature  of  Force.  —Force  may  be  defined  as  that  which 
moves,  or  tends  to  move,  a  body  at  rest,  or  which  changes,  or 
tends  to  change,  the  direction  or  rate  of  motion  of  a  body 
already  moving.  A  familiar  example  of  force  is  met  with 
in  gravitation,  whereby  an  object  has  a  tendency  to  fall  to  the 
ground.  In  order  to  support  it,  an  upward  force  equal  to  the 
weight  of  the  object  must  be  exerted.  The  phrase  "equal 
force"  implies  that  forces  can  be  measured.  In  this  country 
they  are  usually  measured  in  terms  of  weights  in  lbs.,  cwts., 
etc.  Any  one  who  has  seen  a  pulley,  or  lever,  at  work  knows 
that  the  direction  of  application  of  a  force  can  be  changed. 
Evidently,  then,  forces  can  be  represented  graphically.  Lines 
drawn  to  scale  are  employed,  and  these  can  be  arranged  to 
exhibit  at  the  same  time  both  the  magnitude  and  the  direction 
of  the  forces.  Thus,  a  weight  of  10  lbs.  acting  vertically 
downwards  can  be  represented  by  a  vertical  straight  line  10 
units  in  length.  If  the  unit  of  length  be  J",  the  line  will 
measure  ten  times  J'^'^li";  whereas,  if  the  unit  of  force  be 


MECHANICS  OF  CARPENTRY. 


307 


represented  by  a  length  of  1",  the  graphic  representation  of 
"the  force  will  be  a  vertical  straight  line  10"  long. 

Besultant  of  two  or  more  Forces.— (l)  When  two  or  more 
forces  together  act  at  a  point  in  the  same  direction  and  in  the 
same  straight  line,  the  resultant  force  is  equal  to  the  sum  of  the 
components. 

Example. — (a)  If  two  10  lb.  weights  attached  to  a  cord  are 
hung  upon  the  same  nail,  the  resultant  weight  acting  upon  the 
nail  is  10+10=20  lbs. 

(2)  If  two  equal  forces  together  act  at  the  same  point  in 
opposite  directions,  but  in  the  same  straight  line,  they  neutralise 
each  other,  and  the  forces  are  said  to  be  in  equilibrium. 

Example. — A  spring  balance  carries  a  weight  of  6  lbs.    The 
index  finger  of  the  balance  shows  that  the  spring  exerts  an 
upward  force  equal  to  the  downward  force 
— the  weight ;  and  a  state  of  equilibrium  is 
obtained. 

If  the  two  unequal  forces  together  act 
at  the  same  point  in  opposite  directions, 
but  in  the  same  straight  line,  the  resultant 
force  is  equal  to  the  difference  between 
the  forces,  and  is  in  the  direction  of  the 
greater. 

It  is  evident,  then,  that  the  directions 
of  the  forces,  and  therefore  the  angles 
they  make  with  one  another,  must  be 
Considered  in  determining  the  forces  act- 
ing at  any  given  point. 

If  a  flexible  string  be  attached  to  a 
freight,  and  then  passed  over  a  frictionless  pulley,  there  will 
\y%  the  same  tension  in  every  part  of  the  string,  irrespective 
of  any  change  of  direction  caused  by  using  the  pulley. 

To  illustrate  these  facts  clearly,  suppose  that  two  7  lb. 
heights,  connected  by  a  cord,  hang  over  a  smooth  peg  as  shown 
in  Fig.  568.  The  total  weight  on  the  peg,  neglecting  the  weight 
of  the  cord  (which  may  thus  be  any  length),  is  14  lbs.,  the  sum 
of  the  two  weights. 

Again,  suppose  three  such  pegs  in  a  horizontal  straight  line, 
and  the  cord  and  weights  to  be  passed  over  them  as  shown  in 
Fig.  569.    Evidently  the  weight  on  the  ceixtTvxV  \)ft^  \^  tvo\Jk«\^. 


Fio.  668.— Two  forces 
acting  in  the  same  direc- 
tion. 


308       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


Now,  suppose  the  outside  pegs  to  be  lowered  slightly,  as  shown 
by  dotted  lines  in  the  figure ;  the  central  peg  will  now  carry 
a  small  proportion  of  the  weight,  and  the  more  the  outside  pegs 
are  lowered,  the  n^oie  weight  will  be  thrown  on  the  central  peg, 
until,  as  shown  in  Fig.  668,  it  carries  all  the  weight,  i.e,  14  lbs. 
Therefore  the  weight  upon  the  central  peg  varies  according  to 
the  direction  of  the  forces  acting  on  it — from  nothing  in 
Fig.  569  to  14  lbs.  in  Fig.  568. 

The  magnitude  and  direction  of  the  resultant  force  acting 
upon  the  central  peg,  and  upon  each  of  the  outside  pegs,  can  be 
determined  by  the  parallelogram  of  forces. 

B A       c 


c 

Fio.  569. — Arrangement  of  Weights  with  Cords  Fio.  670. — Diagram  show- 

passing  over  Pegs  to  illustrate  the  Parallelogram        ing  the  Forces  acting  on  the 
of  Forces.  Peg  Bu  Fig.  569. 

The  Parallelogram  of  Forces. — if  two  forces  acting  at  a  point 
be  represented  in  magnitude  and  direction  by  the  adjacent  sides  of 
a  parallelogram,  the  resultant  of  these  two  forces  will  be  repre- 
sented in  magnitude  and  direction  by  that  diagonal  of  the  parallelo- 
gram which  passes  through  the  point. 

Example  1. — The  angle  at  A,  when  the  cord  passes  over  the  pegs 
^1,  AjCi,  shown  hy  the  dotted  lines  in  Fig.  569,  is  given.  Determine 
hy  the  parallelogram  of  forces  the  stress  on  the  peg  ^,  i.e.  the  single 
force  acting  through  the  point  J.,  which  shall  he  equal  in  effect  to 
the  forces  AB^,  AC^  acting  together. 

Produce   AB^  and  AC^^  and  mark  off  on  each  line  7  units, 

measuring  from  A.     Then  A\  and  A^  represent  in  magnitude 

and  direction   the  forces  caused  by  the  loads.     Complete  the 

parallelogmm  by  drawing  ID  par«A\e\  Ui  A^,  «j[vd  ^D  i^arallel  to 


MECHANICS  OF  CARPENTRY.  30d 

Al.  The  length  of  the  diagonal  AD,  measured  in  the  same 
units  as  the  lines  ^1  and  A2,  represents  the  magnitude  of  the 
resultant  force — i.e,  the  stress  on  the 
peg  A.  The  direction  of  the  force  will 
obviously  be  downwards.  A  force  re- 
presented in  magnitude  and  direction 
by  DA  would  evidently  counterbalance 
the  force  AD,  and  would  therefore 
counterbalance  Al  and  A2  acting 
together.  Forces  which  balance  each 
other  are  said  to  be  in  equilibrium.  ^^^  57i.-Diagmm  show- 

Example  2.— Determine  the  magnitude  ^^^^^B^Yiim""^^^  **""  *^^ 
and  direction  of  the  single  force  which 

will  replace  the  two  forces  exerted  hy  the  cord  and  weight  on  the 
peg  Bi  (Fig.  569). 

Draw  ab  7  units  long  (Fig.  570)  and  parallel  to  the  cord  Al 
in  Fig.  569.  From  b  draw  be  also  7  units  k>ng  and  parallel  to 
the  cord  below  the  peg  B^.  Complete  the  parallelogram  by 
drawing  dc  and  ad  parallel  to  ab  and  be  respectively.  Then 
the  diagonal  bd  gives  the  magnitude  of  the  required  force,  the 
direction  of  which  is  from  b  to  d. 

Example  3. — Fig.  571  shows  the  application  of  the  parallelo- 
gram of  forces  to  determine  the  resultant  force  on  the  peg  B. 

In  the  above  examples  no  allowance  has  been  made  for  the 
weight  of  the  cord  or  for  the  friction  on  the  pegs.  It  is  assumed 
in  each  case  that  the  forces  are  acting  at  the  point  of  intersection 
of  the  straight  lines  produced. 

Example  4. — Two  forces  of  10  and  6  lbs.  respectively  act  from 
a  point  and  in  directions  which  are  at  right  angles  to  each  other. 
Determine  the  magnitvde  and  direction  of  the  single  force  which 
can  replace  the  two  forces. 

Let  the  line  AB  (Fig.  572)  represent  in  magnitude  a  force  of 
10  lbs.  acting  at  the  point  A  in  the  direction  indicated  by  the 
arrow,  and  AC  di,  force  of  6  lbs.  acting  at  right  angles  to  AB. 
Complete  the  parallelogram  ACDB.  Then  the  length  of  the 
diagonal  AD  represents  the  magnitude  of  the  resultant  force, 
and  the  direction  in  which  it  acta  will  be  from  the  point  A,  as 
shown  by  the  arrow. 

It  must  be  understood  clearly  that  a  resultant  is  a  force 
which  can  take  the  place  of,  and  will  prodwce  t\^fe  «ajai^  ^^^^\. 


310      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


as,  two  or  more  forces.  To  maintain  equilibrium,  the  resultant 
force  must  be  counterbalanced  by  an  equal  force  acting  in  the 
opposite  direction.    The  force  so  acting  is  called  the  equililaraiLt 


m — r>T — I — I — r 


B 


Fio.  572. 


Pia.  573. 


Example  5. — Figs.  673  and  674  show  the  magnitude  and 
direction  of  the  resultant  force  when  forces  of  9  and  6  lbs,  respec- 
tively act  at  angles  of  {a)  120",  {h)  45°. 

The  simple  apparatus  shown  in  Fig.  576  clearlj  illustrates  the 
principle  of  the  parallelogram  of  forces.     On  a  vertical  board 


Fio.  574. 


Fig.  575.— Apparatus  to  illustrate  the  Parallelo- 
gram of  Forces. 


are  fixed  two  small  pulleys  by  means  of  screws,  so  that  they 
revolve  with  as  little  friction  as  possible.  By  making  a  three- 
way  string,  passing  it  over  the  two  pulleys,  and  adding  varying 
weights  to  each  of  the  three  ends  of  the  string,  it  can  be 
demonstrated  clearly  how  the  three  forces  act.  In  Fig.  575 
the  weights  are  respectively  5,  6,  and  4  lbs.  By  drawing  the 
parallelogram  ABDC,  such  that  AB  equals  5  units  in  length, 
and  AC  equals  4  units,  the  d\agoi\a.\.  DA  \a  iowivd  X^vi  w\^'a»w\» 


MECHANICS  OF  CARPENTRY 


311 


6  units,  and  to  represent  the  magnitude  of  the  middle 
weight.  If  other  weights  are  attached  to  the  ends  of  the 
strings,  different  results  will,  of  course,  be  obtained. 

Triangle  of  Forces. — The  triangle  of  forces  is  used  to  deter- 
mine the  magnitude  and  direction  of  any  three  forces  which 
balance  each  other.  The  rule  may  he  stated  as  follows  :  If  three 
forces  acting  at  a  point  are  in  equilibrium  they  can  be  represented 
in  magnitude  and  direction  by  the  three  sides  of  a  triangle  taken 
in  order. 

Example  1. — The  forces  acting  upon  A  {FHg,  575)  are  in 
equilibrium. 

Since  the  length  of  the  line  AS=b  units,  and  the  line 
BD  is  parallel  and  equal  in  length  to  AC =4,  units,  and  the 
diagonal  DA  is  in  a  line  with  the  direction  of  the  middle 
vertical  weight  and  equal  in  length  to  6  units  ;  then  the  sides 
ABy  BD,  and  DA  of  the  triangle  ABD  represent  both  in  magni- 
tude and  direction  the  forces  acting  at  the  point  A. 

To  save  confusion  it  is  usual,  however,  to  draw  a  separate 
triangle  to  illustrate  these  forces.  A  somewhat  different  system 
of  lettering  also  simplifies  the  consideration  of  the  examples. 
This  is  known  as  Bow's  notation.  In  it  the  two  letters  denoting 
a  force  are  placed  one  on  each  side  of  the  line  representing  the 
force,  that  is,  in  the  spaces  between  such  lines.  Thus  in  Fig.  576 
the  three  forces  acting  at  the  point  o  are  referred  to  as  AB, 
BC,  CA  respectively. 


9l^. 


Fio.  576.— Three  Forces  acting  at 
a  PoiDt. 


Fio.  677.— Triangle  of  Forces  for 
Fig.  576. 


Example  2. — Given  the  magnitude  (9  lbs.)  and  the  direction 
{indicated  by  the  arrow)  of  AB,  and  the  angles  which  the  directions 
of  the  three  forces  make  with  each  other ,  it  is  required  to  find  the 
magnitude  and  direction  of  BG  and  CA  when  the  forces  are  in 
equilibrium. 

Draw  the  line  ab  (Fig.  577)  parallel  to  the  direction  of  action 
of  the  force  AB,  .9  units  long,  and  iu  the  direction  a\\o>«i^\i^  Xlfea 


312       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


arrow.  From  b  draw  be  parallel  to  BC  until  it  meets  ac  drawn 
parallel  to  CA.  Then  the  triangle  abc  is  the  triangle  of  forces, 
and  the  direction  of  the  forces  BC  and  CA  can  be  found  by 
taking  the  sides  of  the  triangle  in  order,  viz.  a  to  by  b  to  c, 
c  to  a;  and  these  directions  give  also  the  directions  of  action 
of  the  forces  represented  by  the  lines  parallel  to  ab,  be,  and  ca 
respectively.  Thus  AB  acts  from  the  joint  o  ;  BC  acts  totpards 
o  ;  and  CA  acts /rom  o. 

The    following    examples    show   the    application    of    thesa 

principles   to   simple    practical    ques- 
tions. 

ExAsfPLE  3.—  ^  rope  bears  a  tensile 
stress  (pull)  of  30  cicts.  Find  the  rruig- 
nitude  of  the  stress  in  each  of  two  other 
ropes  which  make  an  angle  of  60"  mth 
each  other,  and  together  balance  the 
stress  in  the  first  rope,  supposing  the 
second  and  third  ropes  are  equally 
stressed. 

Fig.  578  shows  the  application  of 
the  triangle  of  forces  to  the  solution 
of  this  question^  the  answer  giving 
the  stress  in  each  rope  as  17*32  cwts. 
By    going    round    the    sides    of    the 

triangle  in  order,  it  will  be  seen  that  the  force  in  each  of  the 

three  ropes  acts  from  the  joint. 

Example  4. — A  huckling-chain  is  used  to  raise  heavy  blocks  of 
stone.  What  is  the  amount  of  stress  in  the  links  of  the  chain  when 
raising  a  weight  of 
one  ton,  if  the  buck- 
ling-chain  is :  ^ 

{a)   pulled    tightly 
as  in  Fig 

(b)    placed 
round  the 
Fig.  580. 

The     correct    solu-     Fio.  579. — stresses  in  a  Buckling-chain  when  pulled 

tion  of  this  question 

depends  on  (1)  the  weight  of  the  stone  ;  (2)  the  angle  between 

the  forces  AC  and  BC. 


MECHANICS  OF  CARPENTRY. 


313 


The  application  of  the  triangle  of  forces  in  each  case  (Figs. 
579  and  580)  shows  that  the  stresses  AC  and  BC  are  more  than 
twice  as  great  when  the  chain  is 
fixed  as  in  Fig.  579  as  they  are 
with  the  arrangement  in  Fig.  580  ; 
or,  the  tighter  the  chain — i.e.  the 
greater  the  angle  between  the 
forces  BC  and  CA — the  greater  is 
the  stress  on  the  links. 

ExAMPLB  5. — A  triatigular  bracket 
fixed  against  a  wall,  as  shown  in 
^ig.  581,  has  a  weight  of  6  ctots.  sus- 
2>ended  from  the  outer  end  o.  What 
■is  the  nxxtwre  aTid  amount  of  stress 
'in  each  of  the  members  oA  and  oB? 

Fig.  582  is   the  triangle  of  forces  used  to  determine  these 
stresses,  and  is  drawn  as  follows  :  1^^  is  drawn  parallel  to  and 


Fig.  580.— Stresses  in  a  Buck- 
ling-chain  when  placed  loosely 
round  a  load. 


Savts. 


Fig.  681.— Line  Diagram  of  Tri- 
angular Wall-bracket. 


Fig.  582.— Stress  Diagra'ta  for 
Fig.  681. 


Scwts. 


Fig.  583. 


Fio.  584. 


Another  form  of  Wall-bracket  with  Stress  Diagram. 


314       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

represents  the  downward  force  (the  weight  of  5  cwts.)  to  scale. 
From  2,  draw  2i3|  parallel  to  2  3^n  Fig.  581  until  it  meets  \fii 
drawn  parallel  to  I  3.  Then  the  triangle  li2|3j  represents  the 
magnitude  of  the  forces. 

By  going  I'ound  the  triangle  in  order  as  shown  by  the  arrows, 
we  find  that  2  3  acts  towards  the  joint  o  and  is  therefore  a 
compression  stress  or  thrust^  and  3  1  acts  from  the  joint  and  is 
therefore  a  tension  stress  or  pull. 

Fig.  583  shows  a  somewhat  modified  design  of  triangular 
wall-bracket,  and  Fig.  584  is  the  triangle  of  forces  by  which 
the  stresses  in  the  various  members  are  ascertained. 


.  /  .. 


3,"  ^, 

Fio.  685.  Fio.  586. 

Examples  typifying  Simple  Roof  Trusses. 


Fio.  587. 


Example  6. —  What  is  the  nature  and  amount  of  stress  in  each 
of  the  members  AB  and  AC  {Fig,  585)  caused  by  the  weight  o/lO 
ciots,  acting  as  shmon? 

This  example  may  be  taken  as  typifying  a  simple  kind  of 
roof-truas  with  the  weight  taking  the  place  of  the  ridge  piece. 
Re-letter  or  figure  the  diagram  according  to  Bow's  notation. 
"Draw  the  vertical  line  2i3i,  equal  in  magnitude  and  direction 
to  the  weight  2  3.  Complete  the  triangle  by  di-awing  lines 
parallel  to  the  members  AC -dud  AB,  from  the  points  2i  and  3^ 
respectively.  These  lines  represent  the  amount  of  stress  along 
the  members  AC  and  AB.    Ou  taV\\\^  \\i^  wv^^^  ol  \3cvfe  t,^\sv.\i^le 


MECHANICS  OF  CARPENTRY. 


315 


AffZfa. 


in  order  as  shown  by  the  arrows,  it  is  seen  that  2i3i  act  down- 
wards ;  Sjli  acts  towards  the  joint  A,  as  does  also  l^Sj ;  there- 
fore each  member  is  subject  to  a  compression  stress  (thrust). 

Fig.  586  shows  another  example  of  this  kind  with  a  much 
smaller  angle  between  the  forces. 

Fig.  587  illustrates  a  still  further  example,  where  the  two  sides 
are  of  unequal  inclination. 

Polygon  of  Forces. — The  method  of  obtaining  the  resultant 
of  any  two  forces  acting  at  a  point  can  be  extended  to  three, 
four,  or  any  number  of  forces. 

Example.— 0^,  OB,  OC,  OB,  OE,  {Fig,  688)  represent  the 
Tnagnitvde  and  direction  of  five  forces  acting  at  the  point  0. 
Determine  the  magnittide  and  direction  of  the  resultant  force. 

This  problem  can  be  solved 
either  by  an  application  of  the 
parallelogram  of  forces  or  by  a 
direct  construction. 

(1)  Determine  by  the  parallelo- 
gram of  forces,  the  resultant  01 
of  forces  OA  and  OB  (Fig.  589). 
Similarly,  determine  the  resul- 
tant 02  of  the  forces  01  and 
DC.  Again,  OS  is  the  resultant 
of  the  forces  02  and  OD ;  and 
finally  04  is  the  resultant  of 
03  and  OE.  Therefore,  04  is 
the  resultant  of  all  the  original 

forces ;  or,  in  other  words,  a  single  force  equal  in  magnitude 
and  direction  to  the  force  04  will  have  the  same  effect  at  the 
point  0  as  the  five  forces  have  when  acting  together.  Since  a 
force  40  will  balance  04,  a  force  represented  in  magnitude  and 
direction  by  the  line  40  will,  together  with  the  five  given 
forces,  produce  equilibrium  at  the  point  0. 

(2)  The  same  result  may  be  obtained  more  simply  as  follows  : 
Re-letter  the  forces  as  shown  in  italics  (Fig.  589),  and  then,  as 
in  Fig.  690,  draw  a  straight  line  al/  equal  in  magnitude  and 
parallel  to  ab  (Fig.  589).  From  b'  draw  b'c'  equal  and  parallel  to 
be ;  continue  the  process,  taking  the  forces  in  order.  It  will  be 
found  by  drawing  the  closing  line  of  the  polygon,  that  is,  by 
joining  yto  a',  that  a^'a'  gives  the  magnitude  and  V\\^  dVt^cWvya. 


_£'^9lbs 


Fig.   588.— Five  Forces  acting  at  a 
Point 


316       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


of  the  force  required  to  produce  equilibrium.  Conversely,  aV 
is  the  resultant  of  all  the  original  forces.  By  drawing  the  line 
40  through  the  point  0  (Fig.  589)  and  indexing  it  to  scale,  the 


X' 

Vui,  5S9.  Pio.  690. 

Alternate  Stress  Diagrams  for  Fig.  588. 

required  resultant — which  corresponds  with  the  one  determined 
by  the  parallelogram  of  forces — is  obtained.  Its  direction  is 
indicated  by  the  arrow. 


9lbs. 

libs. 

Fio.  601.  Fio.  592. 

Examples  showing  the  application  of  the  Polygon  of  Forces. 

Fig.  592  is  the  polygon  of  forces  when  two  of  the  forces,  he 
and  de^  act  towards  the  joint  (Fig.  591),  the  magnitude  of  all  the 
forces  being  as  in  the  previous  eiLab«i\\fc.     \w  \iVi\a  casA  the 


MECHAmCS  OF  CABPENTRY.  317 

eqiiilibnint  ia  determined,  and  ia  ahown  by  the  thick  line  in 
Figa.  591  and  593. 

Figa.  588  to  593  nhould  be  compared  carefully. 

The  polrei™  of  fijrcea  iiiay  he  stated  as  follows ;  IT  tiro  or 
more  ibrces  act  at  a  point,  tlien,  If  atarting'  at  an;  point  a  Una  tM 
drawn  to  represent  the  magnitude  and  direction  of  the  fIrEt  force, 
and  ftom  tlie  point  thae  obtained  anotlier  line  be  drawn  ilmilarly 
to  represent  the  aecond  force,  and  bo  on  until  lines  have  been  drawn 
representing  each  force, — the  reaoltant  of  all  these  forces  will  be 
represented  by  a  straight  line  drawn  &om  the  Blartlng  point  to  the 
IMlnt  Anally  reached 

Pol.vj;<nis,  [iaralleUigra.iis,  or  triangles,  of  forces,  when  uaed  to 
determine  either  the  leaultaiit  or  the  eiiuilibrant  of  stresaea 
acting  at  a  point,  are  called  reciprocal  diagrams. 

Inclined  Forces  in  one  Plane  but  not  acting  tbroagh  one 
Point. — The  foregoing  examples  deal  only  with  forcaa  which 
net  at  a  single  given  point,  and  in  these  cases  the  resultant  a«ts 
at  the  same  poiiit.  When  all  the  forces  do  not  act  at  the  same 
point,  the  magnitude  and  direction  i>f  the  resultunt  is  obtained 
as  in  previous  examples,  i.e.  by  di'iwing  the  recipivical  diagram  ; 
the  line  of  action,  however,  still  remains  to  be  determined.  To 
determine  this  line  of  action,  it  is  necessary  to  draw  what  is 
known  as  the  fDnloular  or  llnlc  polygon.  The  method  is  as 
follows  ; 

ExAMrLB.— Ze(  X,  Y,Z(Fig.  593)  be  three  forces  in  the  tame 
pla/ie  and  of  the  magnitude  and  direction  shovm.  It  it  required 
to  find  the  magnitude  and  the  line  of  action  of  the  retultaiU 
/or™. 

Re-letter  the  forces  abed  aeooi'ding  to  Bow's  notation  (p.  31]), 
and  draw  the  reciprocal  diagram  a'b'c'd' ;  the  line  a'd'  which 
closes  the  figure  represents  the  magnitude  of  the  resultant.  To 
obtain  the  actual  line  of  action  of  the  resultant,  tuke  any  point 
or  pole  0  and  join  a'O,  b'O,  c'O,  d'O.  The  figure  thus  obtained 
ia  called  the  polar  diagram.  The  funicular  polygon  is  now 
lionstructed  by  drawing.— anywhere  in  the  space  ft— a  line  1  3 
parallel  to  b'O  and  intersecting  the  forces  .1'  and  T  at  1  and  2 
•■eapectively.  FroTii  2  draw  2  3  parallel  to  e'O,  intersecting  the 
force  Z  in  3.  Through  1  draw  1  4  parallel  to  a'O,  and  through 
3  draw  34  parallel  to  d'O.  Through  the  point  of  intersection  4, 
ixyir  a  lino  g  parallel  to  a'tf".     R  is  the  requ^Teii  Ima  cA  w 


318       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


of  the  resultant  of  the  three  given  forces,  and  its  magnitude  is 
represented  by  the  length  of  aid. 


>j  \ 


Pio.  595.— Simple  Lover. 


Fio.  598. 

Method  of  determining  the  Resultant  of  three  Forces  which  do  not 

act  at  the  same  Point. 

Parallel  Forces. — In  addition  to  forces  acting  in  the  ways 
already  explained,  it  is  necessary  to  consider  a  few  examples  of 
parallel  forces.     (These  must  not  be  mistaken  for  those  dealt 

with  by  the  parallelogram 
^      of  forces,  as  they  are  en- 
tirely different. ) 

In  all  the  examples  of 
parallel  forces  now  to  be 
considered,  the  forces  will 
act  vertically.  As  these  can  be  shown  easily  both  graphically 
and  arithmetically,  each  example  will  be  worked  out  by  both 
methods. 

The  simplest  examples  of  the  equilibrium  of  parallel  forces 
are  found  in  the  use  of  levers.  The  lever  shown  in  Fig.  595  is  a 
straight  bar  resting  on  a  triangular  block,  F^  called  a  ftQcroxn. 
At  the  ends  A  and  B  of  the  lever,  forces  P  and  W  respectively 
act  vertically  downwards.  It  is  plain  that  forces  P  and  W  will 
tend  to  rotate  the  lever  in  opposite  directions  around  the  fixed 
point  F.  The  tendency  of  either  force  to  rotate  the  lever  is 
called  the  moment  of  that  force  ;  it  is  measured  by  the  product 
of  the  force  into,  the  perpendicular  distance  (called  the  arm  of 


MECHANICS  OF  CARPENTRY.  Sid 

the  force)  of  the  fixed  point  from  the  line  of  action  of  the  force. 
Wlien  tlie  two  moments  are  equal  tUe  lever  is  in  equilibrium.  The 
conditions  of  equilibrium  therefore  are  : 

PxAF=WxBF. 

If  ^i^be  6'',  BFhe  2^,  and  W=9  lbs,  then  P  will  require  to  be 

9x2 

=3  lbs.  :  the  moment  of  each  force  being  18  inch-lbs. 

Since  moments  are  always  expressed  in  terms  of  the  product 
of  a  force  and  a  length,  both  these  factors  enter  into  every 
statement  of  the  magnitude  of  a  moment.  If  the  distances  be 
expressed  in  feet,  and  the  forces  in  cwts.,  the  moments  will,  of 
course,  be  expressed  in  ft. -cwts.,  and  so  on. 

Example  1. — A  horizontal  bar  3  ft.  long  tias  a  weight  of^  lbs. 
at  one  end,  and  of  4  lbs,  at  the  other  end  {Fig.  596).  Find  the 
point   at    which    the    bar   must    be 

supported  so  that  it  will  rest  hori-      A JB 

zontally.     {Neglect  the  weight  of  the     'jL ^/ J 

bar.)  ^^  O 

Arithmetically. — Since   the  lever  ^iq.  596. 

is  in  equilibrium,  the  total  down- 
ward force  of  6  lbs.  is  balanced  by  an  upward  force  (reaction) 
of  6  lbs.  at  the  unknown  point  of  support,  and  the  moment 
of  the  upward  reaction,  about  any  point,  is  equal  to  the  sum  of 
the  moments  of  the  downward  forces  about  the  same  point. 
Consider  moments  about  A  : 

Moment  of  weight  at  4>  about  ^,  =  2x0. 
„        „        „      „  B      „      A^^^xAB. 
„      reaction  about  ^  =  (2  +  4)  x  ^  X 

.-.    6x^Z=(2xO)  +  (4x^5); 
/.    6^.r=0  +  (4x3); 
/.    ^Z=J^  =  2feet. 

Graphically. — In  the  consideration  of  these  forces  graphically, 
the  polygon  of  forces  becomes  a  straight  line.  A  polar  diagram 
and  a  funicular  polygon  are  required. 

Fig.  597  shows  the  bar  with  the  weights  suspended.  Letter 
the  forces  AB  and  BG.  The  polar  diagram  is  drawn  as  follows  : 
Draw  to  a  suitable  scale,  a  vertical  line  ac^  6  units  long — equal 
to  the  sum  of  the  weights.  From  any  point  0  which  may  be  at 
any  convenient  distance  from  ac^  draw  Oa,  06,  and  Oc.  To 
construct  the  funicular  polygon,   draw,  in  the  ap^e^  B,  lli 


320      A  MANUAL  Ot'  CARPENTRY  AND  JOINERY. 

parallel  to  bo.  From  1  draw  1 S  parallel  to  aO,  and  from  ^  draw 
2S  parallel  to  Oc,  and  produce  it  to  intersect  IS  in  3,  Then  the 
vertical  line  drawn  through  the  point  3  will  give  the  position 
of  the  fulci'um.  If  the  distances  from  this  point  to  the  points 
of  application  of  the  weights  be  measured,  it  will  be  found  that 


,,,,^ 


Fig.  597. — Loaded  Beam,  with  Stress  Diagrams. 

they  are  in  inverse  proportion  to  the  magnitudes  of  the  weights, 
and  that  the  weight  on  the  right  hand  side  of  the  fulcrum, 
multiplied  by  its  arm  of  leverage,  will  be  equal  to  the  weight 
on  the  left  hand  side,  multiplied  by  the  arm  of  leverage  on 
that  side — the  arms  being  one  and  two  feet  respectively. 

Example  2. — Four  weights  of  2,  3,  6,  and  4  Ihs.  respectively 
hang  on  a  bar  as  shown  in  Fig.  598.     Determine  the  point  at 

which  the  bar  must  be  supported 
A  B  C         D       to  rest  horizontally,  the  weight 

'  i J, i.-^'.L-^-'-A^      ^^  ^^^.  ^^^  ^^^^^  neglected. 

A       '  A         r\        A  Arithmetically. — Let  the  re- 

ztbs.  3lbs      Slbs.     4ibs.  quired   point    of    support  be 

Fig.  598.  denoted     by     the     letter    X. 

When  the  bar  is  in  equili- 
brium, the  sum  of  the  moments  about  A  of  the  downward 
forces,  must  be  equal  to  the  moment,  about  A,  of  the  upward 
reaction  at  the  point  of  support. 

.*.    the  downward  moments  about  A 

=(2x0)  +  (3x7)  +  (6xll)+(4xl6) 

=     0     +    21    4-     66      +      60       =147. 


MECHANICS  OF  CARPENTRY. 


321 


The  moment  about  A  of  the  upward  reaction 

=  Sum  of  all  the  weights  xAX 
=(2  +  3  +  6  +  4)x^Z=15^Z; 

15^Z  =  147; 
.-.   ^Z=V^=9|  feet. 

Graphically, — Draw  the  vertical  line  of  loads  ea,  representing 
to  scale  the  sum  of  the  weights  as  shown  (Fig.  599).  Construct 
the  polar  diagram  by  drawing  from  any  point  0  the  lines  eO, 
dO^  cO,  bOj  and  aO.  To  draw  the  funicular  polygon,  draw 
vertical  lines  under  each  weight,  and — starting  anywhere  in 


Pig.  599.— Loaded  Beam  with  Stress  Diagrams. 


the  line  of  the  first  weight  as  at  1 — draw  in  the  space  B  a  line 
1 2  parallel  to  Ob  ;  in  the  space  C  draw  2  3  parallel  to  Oc  ;  in  the 
space  D  draw  3  4  parallel  to  Od.  Through  4  draw  4  5  parallel  to 
eO  and  through  1  draw  1  5  parallel  to  Oa.  The  vertical  line 
drawn  through  the  point  5,  where  these  two  lines  meet,  gives 
the  position  of  the  point  of  support. 

Although  the  application  of  the  lever  as  a  tool  or  machine  is 
an  everyday  occurrence  with  the  workman  in  such  appliances 
as  the  turning  bar  of  the  bench-vice  and  sash- cramp,  the  screw- 
driver, brace,  pincers,  claw-hammer,  grindstone,  treadle  lathe, 
mortising-machine,  etc.,  the  detailed  consideration  of  each  of 
these  cannot  be  entered  into  for  want  of  space.  The  following 
examples  involving  the  use  of  the  crowbar  will  suffice  further 
to  illustrate  the  principles  involved. 

M.C.J.  X 


322      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

Example  1. —  What  f wee  miMt  be  exerted  at  one  end  of  a  crow- 
bar 6  ft.  lonff,  to  raise  a  weight  of  10  cwts,  at  the  other  end:  the 

bar  resting  on  a  fulcrwm  9" 
^-MfOvtn  ^      f'om  the  weight,     {Neglect 

W      6ft    \y^     the  weight  of  the  crowbar,) 

^yg^f  ^        Let   AB   (Fig.  600)   be 

Pio.  600.  the  bar  6  ft.  long,  and  F 

the  fulcrum  at  9"  from  A. 
Consider  moments  in  inch-lbs.  about  F,  Let  x  he  the 
required  force. 

Moment  of  10  cwts.  about  F=9x  10 x  112  inch-lbs. 

Moment  of  x  about  F=  BFx  x={*72  -  9)  x  ar=63  x  x  inch-lbs. 

9x10x112     ,^.  ,, 

.-.   x= ^_ =  160  lbs. 

bo 

Example  2. — A  man  weighing  140  lbs.  is  iising  a  crowbar  b  ft. 
long.  What  rmist  be  the  position  of  the  fulcrum  to  enable  him  to 
balance  a  weight  of  1260  lbs.  at  the  other  end? 

Let  AB  h%  the  length  of  the  bar;  i^  the  position  of  the 
fulcrum  ;  and  x  the  length  of  the  long  arm  in  inches  ; 

then  (60  -  x)  is  the  length  of  the  short  arm  in  inches. 
Taking  moments  about  F^ 

140^17=1260(60-07); 
140.r=75600-1260.r; 
14007 -fl  260a:  =  75600; 
1400a' =75600; 

.'.  x=-^rjj^=b4:  inches  =  4'  6"  =  length  of  long  arm. 

Example   3.—^  P^onnih 

lever   7  ft.    long  is  ^^CUUWs. 

used   as    shown    in      j>---^ —  -  7 f^    •-• -•-«| 

Fig.^Ol.    If  a  force     ^  J2'* 

o/200  lbs.  i^  applied  F,o  (joi. 

at  P  in  the  direction 

of  the  arroWy  what  weighty  placed  at  a  point  12"  from  the  fulcruniy 

can  be  raised  ? 

Taking  moments  in  ft.-lbs.  about  F, 

irxl=200x7; 
.-.    Tr=  1400  lbs. 

Loaded  Be^^ms. — The  determination  of  the  proportion  of 
the  totsl  weight  carried  by  each  aw^p^port  of  a  loaded  beam — 


MKCHANIC.4  OV  CARPENTRY. 

in  other  words,  the  upwai-d  leaction  of  eiich  support  which,  is 
necessarj  to  maintain  equilibrium — aflbrds  a  good  practical 
ejtaniple  of  the  theory  of  parallel  forces. 

Example  1. — A  beam  rests  upon  aiipporls  placed  8  feet  apart^ 
A  weight  of  12  lbs.  is  placed  on  the  beam  at  a  distance  of2ft.frm 
lAe  right-liand  support.  What  proportion  of  the  iceighl  is  carriei 
by  each  of  the  supports,  the  toeight 

of  the  beam  being  neglededf  •slit. 

Arithmetieallg. — In    this    case        i  ■  ^ 

(Fig.  603)  the    downward    force     ^^■■"■*' £"^^ 

(weight)     of    12    lbs.     must    be  Fid.  eai!, 

balanced  by  upward  forces  (re- 
actions) at  the  points  of  support,  reapectively  equal  to  tbf 
pressure  at  these  points,  and  together  equal  to  12  lbs.  ;  and  the 
raoments  of  the  upward  foi'cca  abiiiit  the  point  c  must  be  equal 
.■.  Reaction  at  yl  xJc^IleactioQ  at  BxBc, 
i.e.  Reaction  at  A  :  Reaction  at  B ::  Be:  Ac, 
Simi  of  reactions  „,  ,„  ,  ... 
at  ^  and  5      ■■■  B<:-.(.Bc+Ac)* 

tA  •.\2a)B.::Sc:AR 

general  terms  aa  follows  ; 
Distance  of  that     ^         ,   , 
load  from       :  ^"^th  betwe 
otl.t-r  end  '"'PP"^^' 

Pressure  on  J  :  12  lbs.  : :  rB  :  AB  ; 
ISxffi     12x2 


r  Reaction  at  A  : 


This  n 


Pressure  on  one  end     that 
caused  by  any  load  '  load  " 

therefore 


.   Press  ui*  oi 


J  =  "^ 


=  3  lbs. 


Similarly,    Pressure  on  B 


]2x^e     12x8 


AB 


8 


lbs. 


Graphically.-  -Tig.  603  shows  the  beam  and  supports  with  tb 
load  in  position.  The  polar  diagram  is  drawn  as  follows  ;  Ura* 
a  vertical  line  ab,  representing  the  weight  (12  lbs.)  to  a  suitabhi 
scale.  From  any  point  0,  which  may  be  at  any  convi 
diaCanee  from  ab,  draw  the  ti'iatigle  Oah.  Draw  as  in  the  figure 
a  vertical  lino  directly  under  the  load,  and  one  under  eacfi 
point  o&Bupport,  as  2,  x,  y.  Letter  the  load  AB,  and  the  space 
between   the  supports  G.     These  letters  can   now   be  used   to 


'(euclld,  Bau. 


.,  Proi>a. 


324       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


denote  the  reaction  at  each  point  of  support — i.e,  the  upward 
force  required  to  maintain  equilibrium — which  is  equal  and 
opposite  to  the  pressure  exerted  on  each  support  by  the  load. 
Anywhere  in  x^  as  from  1,  draw,  in  the  space  A^  a  line  1  2,  parallel 
to  aO  ;  from  2,  in  the  space  B,  draw  2  3  parallel  to  hO.  Join 
1  3,  and  through  the  pole  0,  draw  Oc  parallel  to  3 1.  Then  ac 
(on  the  vertical  line  of  loads  ah)  represents  to  scale  the  pressure 


jzlbs. 


Fia.  603.— Loaded  Beam,  with  Stress  Diagrams. 

on  the  left-hand  support,  and  cb  to  the  same  scale  represents 
the  pressure  on  the  right-hand  support. 

As  the  reaction  at  each  end  is  equal  in  magnitude  and  op- 
posite in  direction  to  the  pressure,  ac  gives  the  amount  of  the 
reaction  AG,  and  he  gives  the  amount  of  the  reaction  BC ;  and 
the  sum  of  the  reactions— both  acting  upwards — is  equal  to 
the  total  weight  (12  lbs). 

Example  2. — A  heam  is  loaded  as  shown  in  Fig.  604.  Deter- 
mine the  reaction  at  each  end,  that  is,  the  upward  force  required 
at  each  point  of  support  to  maintain  equilihrium. 

Arithmetically  : 

Reaction  at  ^  due  ^  ^^  ^^  ^  ^  ^  ^^  ^  ^  ^ 
to  weight  at  (7  % 

Reaction  at  A  due     wt.  at  (7 x  CB_5x  13 
••      to  weight  ate    "  AB  ~    16   ' 


MECHANICS  OF  CARPENTRY. 


325 


Similarly, 

Reaction  at  A  due _ wt.  at  2) x DB _ 7x9 

to  weight  at  i)    ~  AB  "16* 

. ,  Reaction  at  A  due _ wt.  at  ^x EB _ 2x2 

to  weight  at  ^    ~  AB  ~   16  ' 

The  total  reaction  at  A 


is  equal  to  the  sum  of  the 
partial  reactions  as  shown 
above  ;  or  it  may  be  ob- 
tained directly  thus  : 

Total  reaction  at  A 


,      O Q_ 


CD 


7' *- 

E 


ZQftt. 


Fia  604. 


(wt.  at  Cv.  CB) +  (wt.  at  DxDB)+(wt.  a.t  Ex  EB) 

AB 
_(5xl3)+(7x9)+(2x2)_132_   , 
-  ^g  T6  ~^*  ^    ^' 

Similarly, 
Total  reaction  at  B 

(wt.  at  Cx  (7il)  +  (wt.  at  Z)x7)^)+(wt.  at  Ex  EA) 

AB 
(5x3)+(7x7)+(2xl4)     92     .,       ^ 


L\^/l  ^lO'  ^05. — Loaded  Beam,  with  Stress  Diagrrams. 

Oraphically. — Construct  the  vertical  line  of  loads,  re()resent- 
ing  to  scaJe  the  sum  of  the  weights  aa  sbowii  m  YV^.  ^Qf^.    ^Vs. 


^ 


tb. 


326       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

the  pole  0,  and  draw  the  dotted  lines  Oa,  Ob,  Oc,  Od.  Letter  the 
loads  and  draw  a  dotted  vertical  line  directly  under  each  load 
and  under  each  support  as  shown.  From  any  point  in  the 
first  line,  draw  in  the  space  A,  a  line  1 2  parallel  to  aO ;  from 
2  draw  2  3  parallel  to  bO;  from  3  draw  34  parallel  to  cO]  |  ^^ 
and  in  the  space  Z),  from  4  draw  45  parallel  to  dO,  Join  1 
to  5,  thus  completing  the  funicular  polygon.  By  drawing  a 
line  parallel  to  5 1 — the  closing  line  of  this  polygon — through 
pole  0,  and  meeting  the  vertical  line  of  loads  at  e,  it  is  found 
that  ea  equals  the  reaction  EA,  and  ed  equals  the  reaction  ED ; 
they  are  together  equal  to  the  sum  of  the  weights  in  the  beam. 

Example  3.^ — A  beam  weighing  6  cwts.  is  loaded  as  shown  in 

Fig,  606.     Determine  the  reaction  at  each  end  necessary  toprodv/ce 

equilibriwm, 
6G¥tg  sOnUs.  ^Ctufta.  acirta.  .rjrru        xu  •   Ui.      r   « 

O     C)     r^      r\  When  the  weight  of  ^ 

\  "~1..      uniform    beam    is    to   be 


%A     C      J)      £      P     ^        considered,    it     may     1l>* 

taken  as  actinsr  half-w£U^ 

Fio.  606.  ■•     ^  xi^  .  A 

between  the  supports,  2X^^ 
thus  adding  half  its  weight  to  each  support.  With  this  diff!^^' 
ence  the  method  used  is  as  in  the  previous  example.  Fig.  6^^ 
shows  the  graphical  solution. 

Stress  Diagrams  for  Roof  Trusses.-  Figs.  608  to  617  sh 
an  application  of  the  foregoing  graphic  methods  to  the  de 
mination  of  stresses  in  roof  trusses.     Fig.  608  is  a  line  diagra 
of  a  king- post   truss   loaded  in  the  usual   way.     It  must 
noticed  that  the  lettering  is  arranged  so  that  every  member 
indicated   by   a   letter  on  etich  aide.     It  is  first  necessary  •^ 
determine  the  amount  of  weight  carried  by  each  point  of  su^     'P' 
port.     This  example  is  simplified  by  the  symmetrical  loadin^  ^^*5 
as  one  half  the  weight  is   cai-ried  by  each  point  of  suppo: 
When  this  is  not  the  case,  the  proportion  of  the  weight  carri 
by  each  support  must  be  determined  first,  by  a  consideratic^^^^*^ 
of  parallel  forces,  as  in  earlier  examples. 

It  is  usual  when  determining  the  stresses  of  such  a  truss,  W^   . 
draw  the  stress  diagram,  shown  in  Fig.  613.     Tliis  diagram  ^^ 

a  combination  of  Figs.  609  to  612,  which  are   only  drawn 
separate  figures  to  assist  in  understanding  the  question  moi 
clearly. 

Fig.  609  is  the  polygon  of  forces  for  the  joint  (1)  at  the  fo 


MECHANICS  OF  CARPENTRY. 


327 


ihe  principal  rafter  on  the  left.  Four  forces  act  at  the  point : 
'  downwards,  BN  the  principal  rafter,  NG  the  tie  beam,  and 

upward  force,   AG — the  reaction  at  the  point  of  support. 

these  four  forces  the  amounts  of  two,  AB  and  AG,  are 
)wn  ;  it  is  required  to  determine  the  nature  and  amounts  of 
!  stress  of  BN  and  of  NG  when  acting  at  the  angles  given. 


6 arts     SC^fts     4-0¥ts.    3C^ts. 

A mB m C  mD  ®  E 


■      •  ^  V  i  I— — — ^^— ^"'^  /^  V 


/U.      FiQ.  607.— Loaded  Beam,  with  Stress  Diagrams. 


IJommence  Fig.  609  by  drawing  ah  equal  to  AB^  and  ag  equal 
AG^  the  upward  force.  As  these  two  forces  are  in  the  same 
light  line,  and  in  opposite  directions,  their  resultant  is  the 
3  hg.  From  h  draw  hn  paiallel  to  BN ;  and  from  g  draw  gn 
•allel  to  GN  until  hn  and  gn  meet.  Then  hng  is  the  polygon 
triangle  in  this  case)  of  forces  acting  at  the  point ;  and  hn 
1  ng  represent  the  amount  of  stress  in  the  principal  rafter  and 
•beam  respectively. 

rhe  direction  of  the  stress  is  found  by  taking  the  forces 
order  :    thus,  gh  acts  upwards  ;    hn  acts  towards  the  joint. 


328      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


Fio.  609. 


Fio.  608. 


t 

i 

t 

(i 
0 

ar 

]\ 
2i 

^^ 
!(»' 

\o 


Fio.  613. 


-H^ 


Fio.  611. 
Line  Uiagrani  of  King-post  Truss,  with  Stress  Diagrams. 


MECHANICS  OF  CARPENTRY.  329 

therefore  this  member  is  in  compression  ;  ng  acts  from  the 
joint,  which  indicates  that  the  tie-beam  is  in  tension. 

At  joint  (2),  four  forces  act,  namely,  BG,  BN,  CM^  and  NM, 
The  two  known  forces  are  BC  acting  downwards  and  BN 
towards  the  joint.  For  the  magnitude  of  the  stress  on  BN  has 
already  been  found,  and  its  direction  of  action  at  joint  (2)  is  the 
opposite  to  its  direction  at  joint  (1).  Fig.  610  shows  the  appli- 
cation of  the  polygon  of  forces  to  this  joint.  In  it,  he  and  hn 
are  drawn  equal  and  parallel  to  BC  and  BN  respectively  ;  and, 
by  drawing  nm  parallel  to  NM  and  cm  parallel  to  CM^  the  stress 
diagram  is  obtained.  This  shows  that  the  stress  in  CM,  the 
upper  part  of  the  principal  rafter,  is  much  less  than  in  BN,  the 
lower  part.  By  tracing  the  polygon,  it  is  found  that  he  acts 
towards  the  joint,  cm  towards  the  joint  (therefore  CM  is  in 
compression),  mn  towards  the  joint  (compression)  and  nh 
towards  the  joint  (compression  as  in  the  previous  figure). 

At  joint  (3)  there  are  four  forces,  i.e.  CM,  CD,  DL,  ML,  acting 
as  shown.  Of  these  four  forces  the  two  CM  and  CD  are  known. 
Since  the  amount  and  nature  of  the  stress  in  any  member  must 
be  the  same  at  any  intermediate  point  between  the  joints,  the 
stress  in  CM  acting  upon  joint  (3)  must  be  as  determined  by 
the  diagram  for  joint  (2).  Fig.  611  is  the  stress  diagram  ;  cd  is 
drawn  parallel  and  equal  to  CD  ;  cm  parallel  and  equal  to  CM ; 
ml  and  dl  are  drawn  parallel  to  ML  and  LD  respectively  until 
they  meet.  Taking  these  forces  in  order,  cd  is  towards  the 
joint,  DL  towards  the  joint  (compression),  LM  is  from  the  joint 
(tension),  and  MC  towards  the  joint  (compression). 

The  tension  stress  in  LM  is  caused  by  the  struts  MN  and 
LH,  which  transfer  part  of  the  loads  BC  and  DE  respectively 
to  the  foot  of  the  king-post.  If  no  struts  existed  in  this  truss 
there  would  be  no  stress  in  ML. 

Joint  (4)  has  five  forces  acting,  each  one  of  which  has  already 
been  determined,  since  the  stress  diagrams  for  one  side  of  the 
truss  are  in  this  example  applicable  to  each  side.  For  example, 
the  diagrams  showing  the  stresses  in  the  joints  (1)  and  (2)  are 
applicable  to  (6)  and  (5)  respectively.  An  examination  of  Fig. 
612  will  show  that  gn  is  |>arallel  and  equal  to  GN ;  nm  is 
parallel  and  equal  to  NM ;  Im  is  parallel  and  equal  to  LM ;  and 
Ih  being  drawn  parallel  to  LH  meets  mn  in  n,  whilst  hg  is  equal 
to  7ig.  The  diagram  therefore  shows  the  stress  in  each  of  the 
five  members. 


330       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


In  Fig.  613,  which  is  the  complete  stress  diagram  for  the 
members  of  the  truss,  the  lettering  is  identical  with  that  in  each 


Fio.  6H. 


Fio.  615. 


^      f       W 


Fio.  617. 
Types  of  Roof  Truas.  with  Stress  Diagrams. 

of  the  separate  Figs.  609  to  612,  and  will  be  easily  understood 
from  them. 

Fig.  614  is  a  line  diagram  of  a  queen -post  roof  truss,  and 


MECHANICS  OF  CARPENTRY.  331 

Fig.  615  is  the  stress  diagram  of  this  truss.  Similarly,  Figs. 
616  and  617  are  respectively  the  line  diagram  of  and  the  stress 
diagram  for,  a  composite  roof  truss,  sometimes  named  a  German 
truss.  The  detailed  explanation  already  given  will  enable  the 
figures  to  be  understood. 


STBENQTH  OF  WOODEN  BEAMS. 

For  the  purpose  of  calculating  the  carrying  capacity  of 
"wooden  beams,  it  is  necessary  to  notice  the  nature  of  the 
stresses  to  which  they  are  subjected,  as  well  as  the  manner  in 
T^hich  they  are  loaded,  and  the  arrangement  of  the  load. 

Stress  and  Strain. — When  a  weight,  or  other  force,  acts 
upon  a  beam,  it  tends  to  change  the  shape  and  size  of  the  beam. 
The  force  is  technically  called  a  stress,  while  the  change  in 


"mn. 


VrTfTTT 


Fio.  618. — Bcarn  cut  to  illustrate  Stresses. 

shape  or  size  is  called  a  strain.  When  a  beam  or  girder,  sup- 
ported at  both  ends,  is  loaded,  the  upper  part  tends  to  shorten. 
The  lower  fibres,  on  the  other  hand,  are  in  a  state  of  tension,  as 
they  tend  to  stretch.  The  force  acting  on  the  upper  fibres  of 
such  a  beam  is  therefore  a  coxx^ression  stress  ;  that  on  the  lower 
fibres  is  a  tension  stress. 

The  existence  of  these  stresses  may  l)e  made  very  apparent 
either  by  making  a  saw-cut  across,  or  by  actually  cutting  out  a 
wedge-shaped  piece  from,  the  uiiddle  of  a  beam  of  wood  for  half 
its  depth,  as  shown  in  Fig.  618.  On  resting  the  beam  on  two 
supports  with  the  cut  edge  uppermost,  and  then  loading  it,  it 
will  be  seen  that  the  saw-cut  closes.  This  shows  that  the  fibres 
on  the  upper  side  are  in  a  state  of  compression.  If  the  same 
beam  is  now  turned  over  so  that  the  saw-cut  is  on  the  lower  side, 
and  again  loaded,  the  tendency  is  for  the  cut  to  open,  thus 
showifig  that  the  fibres  on  the  lower  side  are  in  a  state  of 
tension. 

Shearing  Stresses. — A  shearing  stress  is  one  which  gives 
the  fibres  of  the  wood  a  tendency  to  slide  over  one  another. 
A  shearing  stress  may  be  either  in  the  direction  of  the  fibref 


332       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

at  right  angles  to  them.  To  illustrate  a  shearing  stress  in  the 
direction  of  the  fibres  of  a  beam,  imagine  the  beam  cut  into  a 
number  of  boards  ;  place  these  on  the  top  of  each  other  in  the 


Fio.  620. — To  illustrate  Shearing  Stress  across  the 

Fibres. 


Fig.  619.— To  illustrate  Shearing  Stress  in  the  direction  of  the  Fibres. 

position  of  a  beam  resting  upon  supports  at  each  end,  and  place 
a  load  in  the  middle.  The  result  will  be  that  the  beam  will 
bend,  as  shown   in   Fig.   619,  and  the  boards  will  slide  over 

each  other.     A  shear- 
ing stress   across   the 
fibres  of  a  loaded  beair»- 
can  be  illustrated  by 
taking  a  bar  of  soap^ 
or    some     such     sofO 
material,  resting  it  upon  supports,  and  loading  it.  .  The  result> 
will  be  as  shown  in  Fig.  620. 

Methods  of  Arranging  Beams.— The  nature  and  amount  of 
stress  in  the  fibres  of  a  loaded  beam  depend  upon  the  way  the 
beam  is  supported  and  on  the  arrangement  of  the  load.     Thus 
a  cantilever  is  a  beam  with  one  end  only  secured  upon  a  support, 
the  other  end  overhanging.     The 
load  upon  a  cantilever  may  be  a 
concentrated    load  at   the   outer 
end,  as  in  Fig.  624,  or  the  load 
may   be   anywhere   between  the 
outer    end    and    the    supported 
end  ;  a  number  of  loads  of  vary- 
ing weights  may  be  distributed 

over  the  length  ;  the  load  may  be  a  uniformly  distributed  one 
extending  over  the  length  of  the  beam,  or  it  may  be  a  com- 
bination of  a  concentrated  load  and  a  distributed  load.  A 
cantilever  loaded  in  any  of  the  ways  just  described  has  the 
fibres  in  the  upper  edge  in  a  state  of  tension,  those  in  the 
lower  half  being  in  compression  (Fig.  621). 

A  beam  supported  at  both  ends  may  be  loaded  in  any  of  the 
ways  described  for  the  cantilever,  with  the  result  that  the 
stresses  will  be  as  shown  in  Fig.  622  ;   i,e,  the  upper  part  will 


k.y^ 


Tension 


Sfsmm 


CompressVMi  - 


3 


-  .J 


Fio.  621. — A  beam  fixed  as  a 
Cantilever. 


STRENGTH  OF  WOODEN  BEAMS.  333 

be  in  compression,  and  the  lower  half  in  a  state  of  tension. 
The  stresses  in  the  various  parts  of  a  loaded  beam  which  has 
the  ends  fixed  differ  from  tliose  of  the  beam  which  simply 
rests  upon  supports.  They  are  illustrated  in  Fig.  623,  which 
shows  that  for  a  distance  of  about  one-fourth  from  each  end 
the  beam  takes  the  form  of  a  cantilever,  and  has  the  fibres  in 
the  upper  half  in  a  state  of  tension  and  the  lower  fibres  in 
compression.    The  remainder  of  the  beam  has  the  upper  fibres 


Compresajjorv 


I 
Fio.  622. — Beam  supported  at  both  ends. 

in  compression  and  the  lower  part  in  tension.  The  neutral 
axis  of  all  these  beams  is  in  the  centre  of  the  depth.  If  a  long 
beam  has  intermediate  supports  as  in  Fig.  623,  it  may  be 
regarded  as  being  "fixed"  at  the  points  of  intermediate 
support. 

Bending  Moments. — For  the  purpose  of  making  comparisons 
of  the  relative  strengths  of  loaded  beams,  a  further  consideration 
of  the  "  moment  of  a  force  "  is  necessary.     Since  the  tendency 


C'--  ■ 


i — ^r r 

-i— :l^-;■--^^-:^- 


\ 

Fio.  623.—  Beam  fixed  at  the  ends. 


i 


to  bending,  to  which  a  given  beam  is  subject  at  any  point, 
depends  upon  the  moments  of  the  stresses  about  that  point,  it  is 
obvious  that  the  relative  strengths  of  beams  may  be  measured 
in  terms  of  moments.  The  bending  moment  at  any  given  section 
is  the  algebraic  sum  of  all  the  external  forces  acting  on  one  side 
of  the  section.  Since  it  is  at  the  point  where  the  greatest  bend- 
ing moment  occurs  that  the  beam  is  subjected  to  the  greatest 
stress,  it  follows  that  it  is  of  some  importance  to  be  able  to 
determine  the  bending  moment  of  beams  loaded  under  different 
conditions.  The  bending  moment — like  other  moments — must 
always  be  expressed  in  terms  of  a  length  and  a  force. 


334      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

Example  1. — A  cantilever  carries  a  load  of  6  tons  at  its  outer 
end,  which  is  5  ft,  from  the  supporting  wall.  Determine  the  maxi- 
mum bending  moment,  and  also  the  bending  mom£nt  at  2  ft.  from 
the  vxill. 

The  greatest  tendency  to  bending  will  be  at  the  point  of 
support,  i.e.  at  a  distance  of  5  ft.  from  the  load. 

.*.   Maximum  bending  moment  =  5  *x  6  =  30  ft.-tons. 

Bending  moment  at  2  ft.  from  the  wall  {i.e.  3  ft.  from  the  load) 

=  3x6  =  18ft.-tons. 

The  bending  moment  at  any  distance  from  the  load  may  be 

determined      graphically 

,         I J  ft    . j^    by   drawing,   as    in   Fig. 

;         i  STon&^k   624,  a   vertical    line  AB 

f^""^ 5 J     30  units  long  (represent- 

C  ing  the  maximum  bend- 
ing moment)  under  the 
point  of  support  A  {i.e. 
the  point  where  the 
bending  moment  is  a 
Q^**^  maximum),    and    joining 

BC.     Then    the  bending 

Fio.  624.— Side  Elevation  of  a  Cantilever  with    nioment    at    the    point   a 
a  Concentrated  Load  at  the  outer  end.  .1,     i  -,    •, 

will    be    represented   by 
the  length  of  ab  drawn  parallel  to  AB. 

Example  2. — A  cantilever  projects  4  ft.  and  carries  a  uniformly 
distributed  load  of  8  ciuts.  along  the  upper  edge.  Determine  the 
maximum  bending  moment,  and  also  draw  a  diagram  from  which 
the  bending  moment  at  any  section  along  the  length  of  the  cantilever 
may  be  determined. 

A  load  arranged  as  shown  in  Fig.  625  is  equivalent  to  a  con- 
centrated load  of  8  cwts.  acting  in  the  middle  of  the  length,  i.e. 
2  ft.  from  the  point  of  support.  The  maximum  bending  moment 
will  therefore  be  8  x  2  =  16  ft.-cwts. 

Fig.  625  is  the  diagram  from  which  the  bending  moment  at 
any  section  may  be  determined.  The  load  is  supposed  divided 
into  4  equal  parts,  and  the  bending  moment  due  to  each  part 
is  drawn  to  scale  on  the  vertical  line  AE.  The  weight  of  Z 
acts  at  3'  6"  from  A,  and  the  maximum  bending  moment  due 
to  ^=2x3*5  =  7  ft.-cwts.     Draw  AB  1  units  long.     Similarly, 


STRENGTH  OF  WOODEN  BEAMS. 


335 


Caiitilevei'  with  a  distributed  Load. 


the  maximum  bending  moment  due  to  F=2  x2*5  =  5  ft.-cwts., 
and  ia  represented  by  BC ;  maximum  bending  moment  due  to 
X=2x  1*5  =  3  ft.-cwts.,  represented  by  CD  ;  maximum  bending 
moment  due  to  If =2  x  0*5  =  1  ft.-cwt.,  represented  by  DE.  The 
maximum  bending 
moment  due  to  the 
total  load  is  therefore 
7  +  5  +  3  +  1  =  16  ft.- 
cwts.,  and  is  repre- 
sented by  AE.  Draw 
a  vertical  line  through 
the  centre  of  each  part 
of  the  load,  and  com- 
plete the  triangles 
AaB,  BbC,  CcD,  DdE. 
Draw  an  even  curve 
touching  the  lines  Ed, 
Dc,  Ch,  Ba.  This  curve 
is  a  parabola.  The 
bending  momeiit  at  any 
section  P  is  represented 
by  the  leiicfth  of  the  vertical  line  PQ  (netting  the  parabola  at  Q. 

The  following  formulae  are  used  for  determining  the  relative 
bending  moments  (and  therefore  the  relative  strengths  required) 
of  beams  loaded  in  various  ways.  In  each  case  Z=the  length 
bf  the  beam  and  W=  the  weight  of  the  load. 

Maximum 
Bending  Moment. 

Cantilever  fixed  at  one  end  and  loaded) 

at  the  other  end  (Fig.  624),  J 

Cantilever  fixed  at  one  end  and  loaded\ 

with  a  uniformly  distributed  load,  / 
Beam    supported  at    both    ends  and\ 

loaded  with  a  central  load  (Fig.  626),/ 

Beam    supported    at   both   ends   and 

loaded  with  a  uniformly  distributed 

load  (Fig.  629), 
Beam  fixed  at  both  ends  and  loaded  1 

with  a  central  load  (Fig.  628),  J 

Beam  fixed  at  both  ends  and  loaded  1 

with  a  uniformly  distributed  load,    / 


WL 

WL 
2 

4 

WL 

8 

WL 

8 
WL 

12 


Relative 
Strength. 

1. 


2. 


4. 


8. 


8. 


12. 


336      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

Figs.  626  to  629  show  beams  loaded  in  various  ways,  and  serve 
to  illustrate. the  method  of  determining  graphically  the  bending 
moment  at"  any  section  of  the  beam. 

It  will  be  noticed  that  the  maximum  bending  moment  of 
a  beam  supported  at  each  end  is  in  each  case  in  the  line  of  the 
load,  and  with  a  central  or  an  evenly  distributed  load  is  at 
the  middle  of  the  length  of  the  beam. 


Fig.  626. 


Fia.  627. 


iLda 


Pio.  628.  Fia.  629. 

Examples  of  Loaded  Beams,  with  Bendiug  Moment  Diagrams. 

Calculation  of  the  Transverse  Strength  of  Wooden 
Beams. — Other  things  being  equal,  the  strength  of  a  rectan- 
gular wooden  beam  is  directly  proportional  to  the  breadth  in 
inches  multiplied  by  the  square  of  the  depth  in  inches,  and 
inversely  proportional  to  the  length  in  feet.  Of  course  the 
nature  of  the  material  is  also  an  important  factor,  since 
timber,  even  of  the  same  kind,  varies  in  strength  to  a  con- 
siderable extent.  Each  beam  therefore  has  what  is  called  a 
natural  constant,  which  must  be  considered  in  the  calculation 
of  its  carrying  capacity.  To  obtain  this  constant,  it  is  usual  to 
take  a  bar  of  similar  wood,  1  inch  square  in  section,  and  long 
enough  to  allow  of  its  being  placed  on  supports  1  foot  apart. 
The  constant  is  the  weight  of  the  central  load,  which  is  just 
sufficient  to  break  the  bar.     The  constant  may  be  expressed 


STRENGTH  OF  WOODEN  BEAMS.  337 

in  lbs.,  cwts.,  tons,  etc.,  and  the  carrying  capacity  will  always  be 
in  the  same  terms.  The  following  constants  (in  -cwts.)  may 
be  adopted  for  the  purposes  of  calculation  :  oak,  asK  and  pitch 
pine,  5  ;  red  deal,  red  pine  and  beech,  4  ;  white  deal  and  yellow 
pine,  3. 

Another  important  consideration  is  the  ratio  which  the 
breaking  load  of  a  beam  bears  to  the  "  safe "  load.  This 
ratio  is  called  the  factor  of  safety,  and  its  value  depends  upon 
whether  the  load  is  a  live — a  constantly  moving — load,  or  a  dead 
(i.e.,  a  stationary)  load.  The  factor  of  safety  for  a  dead  load  is 
usually  taken  at  5,  which  means  that  the  safe  load  upon  a  beam 
must  not  exceed  one-fifth  of  the  breaking  load ;  the  factor  of 

safety  for  a  live  load  is  often  taken  at  10. 

hd'^c 
For  beams  supported  at  both  ends  the  formula  Tf =— ^  may 

be  used  for  the  purposes  of  calculation  when  : 

ir=  breaking  weight  or  maximum  carrying  capacity  of  a 
centrally  loaded  beam,  expressed  in  the  same  terms 
as  the  constant, 

6= breadth  of  the  beam  in  inches, 

0?=  depth  of  the  beam  in  inches, 

L  =  length  of  the  beam  in  feet, 

c=the  constant,  found  by  experiment  as  described  above, 
and  expressed  in  terms  of  lbs.  or  cwts. 

To  illustrate  the  above  formula,  take  two  pieces  of  the  same 

liind  of  wood  say  7  ft.  long,  6  in.  wide  and  2  in.  thick.     Place 

one  of  these  pieces  flat,  and  the  other  one  on  edge,  the  distance 

\)etween  the  supports  in  each  case  being  6  ft.     As  the  constant 

is  the  same  in  both  (say  5  cwts.),  the  carrying  capacity  of  each 

od^c 
will  be  expressed  by  the  formula  W^=— i^; 

for  the  flat  beam,  W=  ^J^l2^^  =  20, 

for  the  one  on  edge,      W= =  60  ; 

and  the  relative  strengths  will  be  as  20  :  60  or  as  1  :  3. 
When  it  is  necessary  to  find  other  terms  than  W^  the  equation 

r   TO 

Tr=— =r^  may  be  expressed  as  follows  : 

Id^c,  WL,  WL_    ^_JWL.  WL 

^ — w  "'cP^'  "^'bc'  "^'y  be  '  "' b(P- 


338       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

The  value  of  W  for  a  distributed  load  is  twice  that  for  a 
concentrated  load,  i.e.  W=  —j — .  When  the  ends  are  fixed  the 
carrying  capacity  is  increased  by  about  one-half. 

For  safe  central  loads  the  formula  ^=-7^  is  used :  F  being 

the  factor  of  safety. 

Example  1. — Find  the  maadmum  carrying  capacity  of  a 
centrally  loaded  wooden  beam  of  pitch  pine^  ^^  ft'  long  (12/5. 
between  the  supports),  10  in.  laide,  and  6  in.  thick,  (1)  when  placed 
on  edge  ;  (2)  when  placed  flat.     Assume  a  constant  of  b  cwts. 

Applying  the  formula 

>r  =— J-,  (1)    W= _  -      -  =250  cwts.  when  on  edge. 

(2)   W= =150  cwts.  when  placed  flat. 

Example  2. —  What  would  be  the  maximum  safe  load  to  which 
the  beam  in  Ex.  1  onay  be  subjected  (1)  as  a  central  loa>d;  (2)  as  a 
uniformly  distributed  load? 

Formula  for  safe  central  load  using  a  factor  of  safety  of  5,  is 

Safe  central  load =-7-7;^ 

6x10x10x5     ^^       ^     r      1  J 

-  ^  50  cwts.  for  beam  on  edge, 


12x5 
or         = z-^r — r = 30  cwts.  for  beam  placed  flat. 

Iz  X  D 

Formula  for  safe  uniformly  distributed  load,  again  using 
factor  of  safety  of  5,  is 

Safe  distributed  load=  ^w- 

2x6x10x10x5     ,^       .     .     ,  , 

= ^jo — e =100  cwts.  for  beam  on  edge, 

2x10x6x6x5     ^^       ,     .     , 
or         = zrz. — =  60  cwts.  for  beam  placed  flat. 

iz  X  5  *^ 

Example  3. — Find  the  breadth  of  a  beam  of  oak  resting  upon 
supports  18  feet  apart,  the  beam  being  12  in.  deep,  to  carry 
safely  a  uniformly  distributed  load  of  5  tons.     Constant  5  cwts. 

Safe  distributed  load,  W=  ; 

.         jr£j'^(6x20)x  18x5^25^ 

••  %d?c       2x12x12x5       4     *'4  '"<=nes. 


STRENGTH  OF  WOODEN  BEAMS.       339 

Example  4. — A  beam  of  red  or  yellow  deal  20  ft.  long 
{between  supports),  and  10  in.  broad  has  to  cairi/  safely  (I)  a 
central  load,  (2)  a  distributed  load  of  4  tons.  What  must  be  the 
minimum  depth  of  the  beam  in  each  case?    {Constant  4  cwts.) 

With  a  central  load  d^  =  — ^ —  ; 

be 

/.   ^=  V-&^  =  V-^0~x4~  =^200=14-14  inches. 

With  a  distributed  load 

.'fWLF    ^/80x20x5      ,—-     _.     ^ 
^=V-267  =  V2xl0x4=^^Q^^  =  ^Q^^"^"^' 

Example  5. —  What  size  of  beam  is  required  to  carry  safely  a 
central  load  of  ^b  cwts.  over  a  \0  ft.  span;  the  depth  and  breadth 
of  the  beam  being  in  the  proportion  of*l\hf    {Constant  5  cwts.) 

b=^^d; 
WLF 


d^b  = 


c 


t.tS.     U/    .  =  CI'  — 

7  C 

bd^^  WLF 

7  ~     c 

„    "JWLF    7x35x10x5     ,^ 

(P= — z = z — = —     =490. 

5c  5x5 

c?=  V490= 7-88"= nearly  8". 

,     5  X  7-88     .  ^  .     , 
.*.   0  =  — = —  =  5'6  inches. 

The  strength  of  flitched  girders  (p.  162)  may  be  calculated  by 
considering  the  wooden  beam  and  iron  flitch  separately.  The 
thickness  of  the  flitch  is  usually  about  ^  that  of  the  wooden 
beauL     The  constant  for  wrought  iron  is  25  cwts. 

Deflection. — In  arranging  beams  it  i.s  necessary  to  consider 
not  merely  the  strength  of  the  beam,  but  also  its  liability  or 
otherwise  to  be  bent  out  of  shape — or  deflected — by  the  load 
placed  upon  it ;  since  a  beam  which  is  overloaded  and  bent  to  a 
large  extent  has  the  fibres  strained  and  therefore  permanently 
weakened.  The  resistance  which  a  beam  offers  to  deflection  is 
called  its  stifEiiess.  It  should  be  noticed  that  the  "strongest" 
beam  is  not  necessarily  the  "  stiff'est,"  nor  the  stifi*est  beam  the 
strongest. 


340       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


It  is  of  importance  to  be  able  to  determine  the  cross-sections 
of  the  strongest  and  the  stiflfest  beams  respectively  which  can  be 
cut  from  a  given  log. 


Fio.  680. — strongest  Beam  from  a  given 
Circular  Section. 


Fio.  681.— Stiffest  Beam  fromaglTen 
Circular  Section. 


Suppose  the  log  is  of  circular  cross-section. 
(a)  To  jmd  the  cross-aection  of  the  strongest  beam, — Draw  a 
diameter  AB  (Fig.  630)  and  divide  it  into  3  equal  parts  at  1 


Fio.  632.  Fio.  633. 

Arrangements  of  Pulleys  and  Weights. 

and  2.  From  1  and  2  draw  perpendiculars  to  ^^  cutting  the 
circumference  at  C  and  D  respectively.  Join  ACBD.  The 
rectangle  A  CBD  is  the  section  required. 

{h)  To  Jmd  the  cross-section  of  the  stiffest  beam, — Divide  the 


MJlLIfyS. 


Ml 


diameter  AB  (Fig,  631)  into  4  equal  parts  at  1,  2,  3,  and  draw 
IC  and  3Z)  perpendiaular  to  ^B,  and  (;utting  the  eireumference 
in  C  and  D  respectively.  The  rectangle  AVBD  is  the  section 
miuired.  ^  ^ 

Since  the  strength  of  a  beam  ia  proportional  to  —f.,  and  the 
value  of  this  fraction  increases  aa  d  increases  when  bd  (i.e. 
the  sectional  area)  remains  constant,  the  Htmngeat  heain  of  any 
given  sectional  area  would  l>e  that  of  greatest  depth  if  the  ten- 
(iencj  to  buckling  could  be  avoideil.  In:  the  case  of  floor  joistg  the 
i-atio  of  depth  to  hreadth  is  often  aa  3  : 1  or  even  4:1,  and  the 
tendenoy  to  buckling  ia  overcome  by  strutting.  The  strongest 
beam  ia  that  which  has  the  depth  to  the  breadth  as  7  : 5. 


P10.6M.— T«o-t 


a.  63S.— ThrH-Shuvidd  FuUej  mock. 


Pulleys. — It  ia  necessary  to  consider  one  or  two  Bimple 
arrangementa  by  which  pulleys  are  used  fnr  hoisting  purposes. 
In  the  following  examples  the  friction  will  for  the  aalte  of 
ainiplicity  lie  neglected,  although  in  practice  it  must  be  taken 
Fig.  632  illustrates  the  simplest  application  of 
It  ia  plain  that  when  the  forces  acting  on  the 
n  equilibrium  they  ai'e  equal,  and  the  only  advantage 
n  the  change  of  direction  of  the  force  required  to 
balance  If.     Therefore  in  this  example  P=  IF. 

In  Fig.  633  the  force  balancing  P  is  the  tension  of  the  cord  A, 
which  is  equal  to  tlirit  of  J3.    The  *"»i  of  theae  two  equal  tenaiona 

is  plainly  equal  to  the  weight   W.     Therefore  -P=-h"i  ^^^  ^^'' 
mechanical  advantage  ia  2. 

Figs.  634  and  635  are  illustrations  of   a   two-  and  a  three- 
iheaved  pulley  block  respectively.    By  arranging  puileya  aide 


the  pulley, 
pulley  ai 


342      A  MANUAL  OF  CARPENTRY  AND  JOINERY.  I 

by  aide  in  this  manner,  and  using  a  combinatioa  of  two  aiinilar  ' 
blocks  as  in  Fig.  636  a  niecLanical  advantage  equal  to  the 
number  of  pulleys  around  which  the  rope  pasaea  ia  obtainei 
In  other  worda,  the  power  required  is  equal  to  the  weight 
raised  divided  by  the  number  ot  pnileja 
around  which  the  rope  passes.  Thus  witt 
3  pulleys  in  each  block  there  will  be  aia 
cords,  and  the  power  required  to  balance 
a  weight  of  18  cwta.  will  be  18-H6  =  3cwtfl., 
plus  the  force  required  to  overcome  frictioD 
Specific  OraTity.^me  apecUc  giavi^, 
or  relativa  density,  oT  a  body  is  tha  ratio  of 
tbe  welg:ltt  of  that  body  to  the  weight  of  » 
equal  Tolnme  of  water.  Thua  a  block  of 
wood  weighing  40  lbs.  per  cubic  toot  has  s 
specific  gravity  of  g=;^=0'64  (aince  a  cubic 
foot  of  water  weighs  62'5  lbs.). 

When  a  body  floats  in  water,  and  is  there- 
fore in  equilibrium,  the  weight  of  the  body 
is  balanced  by  an  equal  upward  reaction,  the 
weight  ot  the  water  displaced  being  equal 
to  the  total  weight  ot  the  floating  body. 

ExAMFLK. — A  block  of  wood  9"x9"x9", 
floats  in  water  with  its  upper  mirface  2'5' 
above  the  aurfaee  of  the  mater.  Find  iW 
specific  gravity. 

^=^.^  "f  ttiB  block  is  submerged. 
Fid.  030.— Piiiioy  iiiui:iiB       By  definition,  the  specific  gravity  of  the 

wood  ia  the  ratio  of  the  weight  ot  any 
portion  of  the  block  to  the  weight  of  an  equal  volume  of  water. 
Consider  the  part  of  the  block  below  the  surface  of  tlie  water. 

Weight  of  submerged  part  of  » 


Specitic  gravity  = 


Weight  of  displaced  water  ■ 
Weight  of  aubinevged  part  of  wood 

Weight  of  whole  block 

Volume  of  submerged  part  ot  woikI 

Volume  of  whole  block 


072. 


QUESTIONS  ON  CHAPTER  XII.  343 


Questions  on  Chapter  XII. 

1.  Two  forces  of  16  and  63  lbs.  act  upon  a  point  at  right  angles  to 
each  other.     Find  their  resultant.     (C.  and  G.  Prel.,  1897.) 

2.  Represent  graphically,  to  a  scale  of  J  in.  =  1  lb.  the  resultant 
of  two  forces  of  9  and  13  lbs.  respectively  acting  at  the  same  point : 

(a)  In  the  same  straight  line  but  in  opposite  directions. 
(h)  In  the  same  straight  line  and  in  the  same  direction. 

(c)  At  right  angles  to  each  other. 

(d)  At  an  angle  of  135°  with  each  other. 

(e)  At  an  angle  of  60°  with  each  other. 

3.  The  spur  of  a  field-gate  abuts  in  the  angle  between  the  front 
post  and  the  horizontal  top  rail,  and  is  inclined  at  30°  to  the 
horizontal.  Determine  the  stress  in  the  spur  caused  by  a  boy 
weighing  80  lbs.  swinging  on  the  outer  end  of  the  gate. 

4.  Two  posts  which  meet  at  an  angle  are  inclined  to  the 
horizontal  at  30°  and  60°  respectively,  and  are  in  the  same  vertical 
plane.  Determine  the  stress  in  each  post  caused  by  a  load  of  two 
tons  being  suspended  from  the  point  of  intersection. 

5.  Three  equal  poles  meet  at  a  point  12  feet  high,  their  lower 
ends  being  at  the  angular  points  of  an  equilateral  triangle  of  8  feet 
side.  Find  graphically  the  stress  in  each  pole  when  a  load  of  3  tons 
is  suspended  from  the  joined  upper  ends  of  the  poles. 

6.  From  a  point  draw  six  lines  s(j  that  each  line  makes  an  angle 
of  60°  with  the  next.  Forces  of  5,  6,  7,  8,  9,  10  lbs.  respectively 
act  from  the  point  of  intersection  along  the  lines.  Find  graphically 
the  magnitude  and  direction  of  the  resultant  force. 

7.  With  the  data  of  Q.  6  find  the  resultant  if  the  directions 
of  two  of  the  forces,  viz.  those  of  6  lbs.  and  9  lbs. ,  are  reversed. 

8.  A  king-post  roof  truss,  20  feet  span  and  10  feet  in  height,  has 
a  purlin  on  each  side  resting  on  the  middle  of  principal  rafters, 
under  which  are  the  struts.  The  load  of  each  purlin  is  5  cwts. 
Find,  graphically,  the  strain  on  each  part  of  the  truss.  (C.  and  G. 
Prel,  1897.) 

9.  Explain  the  "parallelogram  of  forces,"  and  use  it  to  find  the 
strains  on  a  king-post  roof  principal  24  ft.  span,  ^  pitch,  the  trusses 
being  6  ft.  apart.     (C.  and  G.  Hon.,  1894.) 

10.  Draw  line  diagrams  of  the  roof  trusses  shown  in  elevation  in 
Figs.  438  and  448.  Assuming  a  concentrated  load  of  one  ton  at 
each  of  the  purlins  and  at  the  ridge,  draw,  for  each  truss,  the  stress 
diagram. 


344       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

11.  A  mason  is  trying  to  move  a  heavy  stone  by  throwing  all  his 
weight  on  the  end  of  an  iron  bar.  He  weighs  1  cwt.  2  qrs.  7  lb., 
and  his  bar  is  6  ft.  6  in.  long,  fulcrum  1  ft.  6  in.  from  the  end. 
How  much  force  is  he  exerting  upon  the  stone  ?  (C.  and  G.  PreL, 
1903.) 

12.  A  man  weighing  175  lbs.  has  to  move  a  block  of  stone 
weighing  IJ  tons  with  a  lever  7  ft.  long.  Determine  the  position  of 
the  fulcrum  in  order  that  the  weight  of  the  man  may  just  move  the 
stone.     (C.  and  G.  PreL,  1904.) 

13.  The  handle  of  a  mortising  machine  is  2  feet  long.  How  much 
more  pressure  would  you  be  able  to  exert,  applying  the  same  force, 
if  the  handle  were  made  1  foot  longer?    (C.  and  G.  PreL,  1898.) 

14.  A  beam  20  ft.  long,  supported  at  both  ends,  is  loaded  6  ft. 
from  one  end  with  a  weight  of  15  cwts.     Determine  the  pressure  at 
each  support,  neglecting  the  weight  of  the  beam.     (C.  and  G.  PreL> 
1904.) 

15.  A  beam  16  ft.  long  is  supported  at  each  end,  and  is  loaded  *^ 
a  point  4  ft.  from  one  end  with  a  load  of  12  tons.     Make  a  sketch 
showing  the  weight  carried  by  each   support.     (C.  and  G.  Pr^^*' 
1902.) 

16.  A  beam  rests  upon  supports  12  feet  apart.     Loads  of  2,    ^ 
and  6  cwts.  respectively  are  placed  at  3  ft.  distances.     Deterrai:*^ 
both  graphically  and  arithmetically  the  reaction  required  at  ea<^ 
end  to  keep  the  beam  in  equilibrium.     Neglect  the  weight  of  tt^ 
beam. 

17.  A  pitch  pine  beam,  12  in.  by  8  in.,  and  17  feet  long,  res*^ 
upon  supports  16  feet  apart.  Determine  the  maximum  carryiu-.^ 
capacity,  the  load  being  in  the  middle  of  the  length,  when  the  beat^ 
is  placed  (a)  on  edge ;  (6)  laid  flat.  Also  find  the  maximum  saf-^ 
distributed  load  which  may  be  placed  on  the  beam  when  (a)  ot^ 
edge  ;   (6)  laid  flat. 

18.  An  oak  beam  12  inches  deep  spans  an  opening  20  feet  wide* 
With  a  concentrated  load  of  9  tons  in  the  middle  of  the  length  ther^ 
are  signs  of  fracture.     Find  the  approximate  breadth  of  the  beam. 

19.  A  beam  of  Memel  fir,  over  an  opening  16  feet  in  the  clear,  S& 
broken  in  the  centre  with  a  load  of  90  cwts.     Required,  the  depth 
and  breadth  of  the  beam  ;  the  beam  being  proportioned  as  5  to  7. 
(C.  andG.  Ord.,  1892.) 

20.  A  beam  over  an  opening  of  12  feet  has  a  safe  distributed  load 
of  7  tons.  What  section  should  it  be  in  Memel  fir,  and  what  if  a 
flitched  girder  is  used.     (C.  and  G.  Hon.,  1892.) 

21.  A  warehouse  floor  has  to  carry  3  cwts.  to  the  foot  super. 
What  size  beams  would  you  use  if  the  width  is  20  ft.  and  the  beams 


QUESTIONS  ON  CHAPTER  XII.  345 

are  10  ft.  apart,  centre  to  centre  ?  If  flitch  beams  were  used,  what 
would  be  their  size  and  what  the  thickness  of  the  flitch  ?  (C.  and 
G.  Hon.,  1895.) 

22.  A  man  sitting  upon  a  board  suspended  from  a  single  moveable 
pulley  pulls  downwards  at  one  end  of  a  rope,  which  passes  under 
the  moveable  pulley  and  over  a  pulley  fixed  to  a  beam  overhead, 
the  other  end  of  the  rope  being  fixed  to  the  same  beam.  What  is 
the  smallest  proportion  of  his  whole  weight  with  which  the  man 
must  pull  in  order  to  raise  himself  ?    (C.  and  G.  Prel. ,  1897. ) 

23.  Describe  a  simple  arrangement  of  pulleys  by  which  a  man 
pulling  with  a  force  of  a  little  over  50  lbs.  might  lift  a  body 
weighing  200  lbs.  Why  is  it  that  with  the  arrangements  proposed 
he  must  exert  a  force  of  more  than  50  lbs.  ? 

24.  How  is  the  specific  gravity  of  any  kind  of  timber  ascertained  ? 
(C.  andG.  Prel.,  1903.) 

25.  What  is  meant  by  the  density  of  timber?  (C.  and  G.  Prel., 
1902.) 

26.  How  would  you  ascertain  that  the  density  of  oak  is  greater 
that  that  of  fir  ?  How  would  you  determine  the  density  of  either  ? 
(C.  andG.  Prel.,  1901.) 


CHAPTER  XIII. 

DOORS  AND  OTHER  PANELLED  FRAMING. 

Doors. — Doors  may  be  either  ledged,  framed  and  ledged,  C7^ 
framed  avd  panelled. 

Lodged  Doors. — Ledged  doors  are  only  used  for  out-building^ 
and  temporary  work.    They  consist  of  narrow  Imttena,  or  board  ^ 
securely  nailed  to  cross  ledges.    Fig.  637  shows  the  back  elevatio 
and  vertical  section  of  a  typical  ledged  door.     The  joints  of  th 
battens  of  which  a  ledged  door  is  constructed  may  be  either 
(i.)  Tongued  and  grooved  ; 
(ii.)  Ploughed  and  tongued  ; 

(iii.)  Rebated. 

To  relieve  the  monotony  of  the  surface,  and  to  hide  any  slight> 
shrinkage  that  may  take  place,  the  edges  of  the  battens  may  b» 
either  beaded  or  V-jointed  (Figs.  639  and  640).     The  outer  edge* 
of  the  cross -ledges  are  usually  chamfered  as  shown  in  Fig.  637. 

Ledged  and  Braced  Doors.— The  ledged  door  above  described 
has  a  tendency  to  droop  at  the  outer  edge.  To  prevent  this 
drooping,  and  also  to  strengthen  the  door,  it  is  customary  to 
insert  sloping  braces  between  the  ledges  (Fig.  638).  Each  brace 
should  slope  upwards  from  the  hinged  edge.  A  door  of  this 
description  is  called  a  ledged  and  braced  door. 

Framed  Doors.— These  doors  aie  formed  by  constructing 
frames  of  wood,  and  fitting  between  the  frames  thinner  vertical 
narrow  battens  (in  framed  and  ledged  doors),  or  thin  boards 
called  panels  (in  framed  and  panelled  doors).  The  object  of 
using  such  a  frame,  either  for  doors,  or  for  any  similar  panelled 
framing,  is  to  obtain  a  structure  in  which  the  tendency  to 
shrinkage,  inseparable  from  the  use  of  wide  pieces  of  timber,  is 
to  a  large  extent  obviated. 


DOORS  ANC  OTHER  PANELLED  FRAMING. 


Terms  used  in  describiiig   Framed   Doors.— The   otit«r 
vertical  membera  at*  called  stjaoa.    During  the  construction  of 


r» 

INI 

"^C" 

^' 

/« 

<i 

1      1 

Aw^ffigg^g^^W-" 


the  donr  the  styles  are  left  about  three  inches  longer  than  the 
finished  door  is  intended  tiD  be  The  projecting  IJ  inches  at 
each  end  of  the  style 
u  called  a  horn 
pifljecting  hoi 
left  on  the 
protect  Its 
until  thedocir  la  finally 
fixed  in  position  at 
which  time  the  horns 
The 
b  tnzontal 
of  a  framed  door 

Sefiaieiis  Viotnlrdbt 
liare  distinctive 
according  to  their  posi- 
tions in  the  door,  e.g.  top  rail,  frieze  rail  (only  used  in  pane"' 
doors),  lode  rail,  and  hottom  rail.    The  inclined  member 


348       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

door — which  are  only  used  in  framed  and  ledged  doors— are 
called  braces.  The  vertical  members  separating  panels  are 
known  as  muntins. 

Joints  used  in  Doors  and  other  Panelled  Framing.—  1 
(1)  The  mortise  and  tenon  Joint  is  used  for  connecting  the  frames 
together,  the  joints  being  secured  with  wedges  and  either  glue 
or  stiff  paint.  The  mortises  are  cut  into  the  styles,  while 
the  tenons  are  cut  on  the  ends  of  the  rails.  The  thickness  of 
the  tenon  is  from  one-fourth  to  one-third  the  thickness  of  the 
framing.  If  a  tenon  is  made  very  wide  in  proportion  to  its 
thickness,  it  is  liable  to  buckle  when  being  wedged,  and  sub- 
sequently to  become  loose  if  any  slight  shrinkage  should  take 
place.  A  tenon  should  therefore  have  a  width  of  not  more 
than  five  times  its  thickness.  The  mortise  should,  moreover, 
be  a  little  wider  at  its  outer  edge,  and  thus  allow  for  the 
insertion  of  the  wedges  by  which  the  framing  is  secured. 

(2)  Haunched  Tenon. — When  part  of  a  tenon  is  cut  off,  so  as 
to  make  its  width  less  than  the  width  of  the  rail,  it  is  known  a& 
a  haunched  tenon.     Such  haunching  is  necessary  in  the  top  anci 
bottom  rails  to  enable  them  to  be  wedged  securely  to  the  style- 
Haunching  is  also  necessary  in  the  lock  rails  (Figs.  642  an(^ 
643)  and  bottom  rails,  so  that  the  proper  proportion  of  th^ 
width  of  the  tenon  to  its  thickness  may  be  obtained,  as  well  a^- 
to  enable  it  to  be  wedged  firmly. 

(3)  Bare-faced  Tenon. — This  form  of  joint  has  one  side  of  the? 
tenon  flush  with  one  face  of  the  rail  (Fig.  642).  Bare-faced, 
tenons  are  used  in  the  lower  rails  of  a  framed  and  ledged  door 
(Figs.  644  to  647). 

(4)  stump  or  Stub  Tenon. — This  term  is  used  for  short  tenons 
such  as  those  which  occur,  for  example,  on  the  end  of  a  muntin. 
Stump  tenons  in  door  framing  are  usually  about  2  inches  long. 

(5)  Double  Tenon. — A  double  tenon  consists  of  two  tenons  cut 
side  by  side  in  the  thickness  of  the  rail  as  shown  in  Fig.  643. 
In  doors  not  more  than  2J  inches  thick,  the  double  tenon  is  only 
used  for  the  ends  of  lock  rails,  and  then  only  in  cases  where  the 
lock  is  fixed  in  the  thickness  of  the  door.  A  lock  so  fixed  into 
the  edge  of  the  door  is  called  a  mortise  lock.  For  thicker  doors, 
double  tenons  may  with  advantage  be  used  at  all  the  joints. 

Framed,  Ledged  and  Braced  Doors. — Figs.  644  to  647  show 
front  and  back  elevations,  together  with  horizontal  and  vertical 
eectioBSy  of  this  type  of  door.    The  names  and  dimensions  of  the 


FRAMED,    LEDGED,    AND   BRACED   DOORS. 


various  i>artB  are  marked  in  the  illustrations.    The  styles  and 
top  rail  are  of  the  same  thickneaa  ;  the  lock  rail,  bottom  rail, 


and  bnu!C«  are  of  lesa  thickneaa  than  the  styles,  being  thinner  by 
the  extent  of  the  thiekueaa  of  the  tiatteiia.     fci\  t\i«  ^Mai«r»«iefc 


860       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

is  flush  on  the  inner  aide.  In  Mg.  646  the  framework  is  Bhown 
stop-chanifered  on  the  inner  face ;  eucli  chamfering  giv«« 
the  door  a  lighter  appeai-anca.  The  i-aila  and  braces  niay  be 
beaded,  or  moulded,  as  an  alternative  to  stop -chamfering.  The 
joints  of  the  framing  of  the  door  under  consideration  are  formed 
Bfi  shown  in  Fig.  642  ;  the  lock  rail  and  bottom  rail  are  then 


Been  to  have  bare-faced  tenons.  The  edges  of  the  styles  are 
rebated,  or  grooved,  to  receive  the  edges  of  the  battens.  The 
edges  of  the  battens  may  be  : 

(i.)  Tongued,  grooved,  and  beaded  (Fig.  639)  ; 
(ii.)  Ploughed,  tongued,  and  V-jointed  (Fig.  640)  ;    or  they 

may  be 
(iii.)  Eebated  as  shown  in  Fig.  641. 

In  arranging  the  braces  for  such  a  door,  the  lower  ends  may 
be  stump-tenoned  into  the  style,  but  ttie  u^i^v  ends  nhould  be 


FRAMED,   LEDGED,  AND  BRACED  DOORS.         351 

ito  the  rail  aa  shown  in  Fig.  646.    If  the  upper  end  of  the 
fits  into  the  comer  as  the  lower  end  does,  it  is  liable  to 

otf  the  joint  between  the  rail  and 

^tyle.       Again,    the    brace    must 

'8    be    arranged   to   support    the 
edge  of  the  door,  the  lower  end 

;  against  the  hanging- style. 

imed,  ledged,  and  braced  doors 

generally    nsied    for    workshops, 

iouaes,    mills,    stables,    the    out- 
ings of  dwelling-houses,  etc.     The 

uid  arrangement  of  the  framing 

e  larger  doors  vary  considerably, 

lepend  u])on  the  position  and  the 

od   of  hanging    them.      In    wide 

vays,  the  door  is  often  made  in     """*  '"'"'"*' 

IB,  bung  folding,  with  a  rebated  joint  between  the  meeting 

i.      Fig.  648  ahowB  the  elevation  of  a  door  of  this  class. 


650  shows  a  high  doorway  usually  found  in  warehouses, 
aia  doorway  two  pairs  of  doors,  arranged  iw  two  \: 
rebated  joints,  are  sho'wn. 


352       A   MANUAL  OP  CARPENTRY  AND  JOINERY. 


Fig.  652  shown  tlie  elevation  of  a,  stable  door  arraii|;ed  in  V" 
heights,  with  a  ventilator  constructed  in  the  upper  door.   The 


elevation  of  a  very  lar 
mill  yard,  warehouse,  oi 


;e  door,  suitable  for  the  entmDce  to     ^"^ 
other  works  is  shown  in  Pig.  649.     Suff'^" 
a   door   is  often   framed  together  S*^ 
that   it   allows   for   the   insertion   <>' 
a  smaller  wicket-door  as  shown  ifl 
the     drawing.        The     doorways     of 
Gothic  buildings — especially  churche* 
— almost     invariably     have    framed, 
ledged,  and  braced  doors.      Pig.  653 
is  the    elevation  of  a  door  of  this 

When  framed,  ledged,  and  braced 
doors  are  fixed  aa  outside  doors,  or  in 
exposed  positions,  it  is  very  necessary 
that  the  upper  edges  of  all  rails  and 
braces  lie  chamfered  ("weathered") 
to  throw  off  win  watei'  ;  and  the 
joints,  both  of  the  framework  and  at 
of  Church  Doori     '^     the  edfteB  o!  the,  1»M«qb,  aa  well  a« 


PANELLED  BOORS. 


S5S 


ks  of  the  rails,  should  be  well  painted  before  the  doors 

together. 

lied   Doors. — ^The    framing    of  panelled   doors  differs 

lat  of  framed   and  ledged  doors  in  that  the  panels — 


Fio. 

654. 

5* 

1 

Top  "^Rail   4-'' 

1 

> 

\A 

1 

• 
■ 
1 
1 
1 

1 
1 

• 
1 

a. 

it: 

1 
1 

1 

:ki 

1 

1 

1 

L.J              *' 

Lock,  rail     ^ 

1 

^':^^npjm^ 

1 
1 
1 
\ 

ill 

)ont 

1^1 

1 

lel 

1^1 

1 
1 

• 

1 
1 

1 

1 

1 
Bottonurail   ?i 

^ i- 

1 

1 
1 

50 


N 


vy 


'--Z'6- ' 

'Lev AT  I  ON 
Horizon taJ  Section. 


Fio.  657.— Panel   in  Stop 
Chamfered  Framing. 


VaUatSechon. 

Flo.  656. 


Fio.  655. 
ion  and  Sections  of  a  Four-panelled  Door. 


are 


FiQ.  658.— Panel  in  Stop 
Moulded  Framing. 


usually    about    one-third    the    thickness    of    the 

it  into  grooves  in  the  middle  of  the  framing.     In  framed 

ged  doors  the  framing  is  put  together,  wedged  up,  and 

before  the  battens  are  nailed  on  ;  whereas  in  panelled 

le  panels  are  iuserted  in  the  grooves  as  \I^ft  ii:^\xi\Xi^  Sa 

z 


■    >x 


au       A   MANUAL  OF  CARPENTRY  AND  JOINERY. 

put  tiigetlier  Thu  grooves  nlso  affect  tlie  width  of  tbfl  ninrttBes; 
an  allrin  tnce  must  tlierefore  be  made  for  the  reduced  width  lA 
the  teiirm>"  which  results  from  the  grooving. 


Fio.  *M) .— Puidlwl  1  mmirib     Single 


PropOTtionB  of  Panelled  Doors.— Since  doore  vary  con- 
siderably in  size,  arrangement,  the  nuiiAier  of  panels,  and  the 
method  of  their  ti'eatniBnt,  no  haiil  and  taat  rule  can  be  laid 
down  as  to  the  proportions  suitable.  For  an  ordinary  dwelling- 
house  door,  however,  the   dimeiiaious   indicated   on  Figs.   6M 


TREATMENT  OF  PANELLED  FRAMING.  355 

and  667  may  be  taken  as  typical.  It  is  important  to  notice  that 
the  height  of  the  centre  of  the  lock  rail  ia  usually  about  S'  9" 
from  the  floor  ;  this  height  is  considered  the  most  suitable  for 
a  lock  or  other  door- fastener. 

Treatment  of  Framing. — When  door  framing  or  other 
panelled  work  is  left  square,  and  the  panels  are  plain,  and  one- 
third  the  thickness  of  the  material  of  the  framing,  the  method 
of  finishing  ia  named  aquaie  and  flat  (Fig.  654).  Square  and  flat 
ia,  however,  improved  upon  by  gtap-chamferlng  (Fig.  657).  stack 
■top  monUUnK  (Fig.  658),  ain^e 
maoldiug  (Fig.  659)  or  bolectlim 
momdliiK  (Fig.  660).  In  the  two 
last-named  an  almost  endless 
variety  of  sections  is  in  use. 
The  treatment  of  the  framework 
around  the  panels  on  the  same 
side  of  the  same  door  ia  of  course 
similar.  In  outer  doors,  the 
thickneaa  of  the  lower  panels  is 
frequently  made  equal  to  two- 
thirds  the  thickneaa  of  the  door. 
In  auch  a  case  one  surface  of  the 
panel  is  flush  with  the  aurface  of 
the  framing.  Figs.  661  and  662 
show  two  methoda  of  treating 
such  a  panel.  In  Fig.  661  the 
bead  runs  round  the  panel ;  this 
treatment  is  known  aa  iMad  flnsli. 
If  the  vertical  edges  only  of  the 
panel  are  beaded,  it  is  named  bei 
thicker  in  the  middle  than  at  the  edges,  ai 

IB  above  the  general  surface,  it  is  known  as  a  ralnd  or  flslded 
pand.  Fig.  663  shows  an  example  of  a  raised  panel,  llie  frame- 
work here  shown  is  sol  id- moulded,  that  is,  the  mould  is  stuck 
on  the  arris  of  the  framing,  whereas  in  single  moulding  and 
bolection  moulding  the  mould  is  "  planted  in  "  after  the  framing 
ia  put  together.  An  important  difierence  ia  necessary  in  the 
preparation  of  framing  where  the  mould  is  to  be  stuck  on  the 
framing — as  compared  with  square  framing,  which  afterwards 
has  the  moulds  planted  in — because  allowance  has  to  be  made, 
in  the  setting  out  and  cutting  of  the  shoulders  of  the  tenons,  for 


T  the  panel  is 
o  that  the  middle  part 


368      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

the  depth  of  the  stuck  moulding.  Moulds  planted  in  are  almost 
invariably  mitred  at  the  angles  ;  but  with  stuck  moulds  a  better 
plan,  wherever  possible,  is  to  scribe  the  joint. 

ScriUng  consists  of  cutting  the  shoulders  of  the  rails  to  the 

profile  of  the  mould  ;  it 

■Slip  Faather 


Augles  of  Moul 


allows  slight   ahrinkage 
to    take    place    without 
visible  effect- 
In       general,      when 
moulds  are    planted  in 
framing,  as  either  single 
or  bolection  moulds,  the; 
are  bradded,  that  is,  fixed 
by  nails  (brads)  paa^g 
thiough  the  mould  into 
the  framing     As,  how- 
ever   the  nail  holes  sire 
framing  the  moulds  if  not  stuck  on 
Rrat  mitred  together  with  dip  foatberB  at  the 


objectionable 

the  framing,  i 

angles  (Fig.  664),  and  are  provided  with  projecting  tongues  at 

the  outer  edges  which  fit  into  grooves  prepared  in  the  framing. 


IS  the  moulds  being  fixed  in  po! 
when  the  framing  ia  being  put  together  ;  it  is  only  used  i: 
best  class  of  framing.     Figs.  665  and  666  show  si 
different  ways  of  filing  moulds  without  nails. 


Foe  1,— Enlnreed  HoiizonUl  Section. 
I  of  s  Fourpandlod  Outer  Door  in  a  3(i 


5B8      A  MANUAL  OP  CARPENTRY  AND  JOINERY. 

Folding  Doors. ^When  doors  exceed  3'  6"  in  width,  and  are 
hung  with  hinges,  it  is  often  advisable  to  have  them  "hung 
folding,"  that  ia,  to  have  the  door  in  two  parts — each  a  Httle 
more  than  half  the  width  of  the  opening  ;  the  joint  where  tbe; 
meet  is  rebated.  The  meeting  styles  are  usually  made  a  little 
narrower  than  the  hanging  styles.  Figa.  680  and  687  show 
examples  of  such  folding  doors. 

Doable  Margin  Doors.— A  double  margin  door  (Fig.  673)  is 
one  which  imitates  a  pair  of  folding  doors  but  opens  as  a 
single  door.    It  is  made  either  as  a  single  door  having  a  veij 


wide  mimtiii,  or  as  two  narrow  doors  fastened  together  with 
hardwood  folding  wedges,  and  strengthened  by  wrought-iroo 
bars,  which  are  fixed  into  the  top  and  bottom  rails.  In  either 
ctse  it  has  a  bead  running  down  the  middle  of  the  door.  Such 
a  bead  is  named  a  double  quirked  or  centre  Iiead.  A  double 
margin  door  is  often  used  for  improving  the  appearance  of  a 
wide  low  doorway. 

Sash  Doors.— Sash  doors  are  those  which  have  the  upper 
part  prepared  for  glass  panels.  The  upper  portions  of  the 
styles  are  generally  narrower  than  the  lower  parts.  Such 
styles  are  named  .umititiiMiiB-  or  gun-stock  styles.  In  the  upper 
part  of  the  door  the  framework  ia  rebated  to  receive  the  glass ; 
while  in  the  lower  part  it  is  grooved  to  receive  the  wooden 
paneh.     To  hold  the  glass  in  position,  smaLl  moulded  wooden 


PANELLED   D00B8 


Fia  67S— Eiilargod  HorbunM  Scctiui 
Detalli,  of  a  Sfi-panollod  Insldo  Door  iB  0.  4^  !lrioli~« 


360       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

filleta  &!«  iiradded  into  the  rebate  in  such  a,  manner  tliat 
they  can  easily  be  removed  when  it  ie  necessary  to  replace 
broken  glass. 

Sash  doors  are  id  general  use  as  the  outer  doors  of  shops ;  ta 

inside  doors  wherever  it  is  desirable  either  to  have  additionil 

light  or  to  see  from  one  room 

to  an  adjacent  roam ;    and  as 

vestibule  doors. 

A  TestlbDle  door  is  a  door 
arranged  in  the  hall  or  passage 
of  a  dwelling  house  or  public 
building.  It  may  consist  of  ft 
sash  door  hung  to  a  rebated 
frame,  and  have  a  width  nearly 
equal  to  the  width  of  the  pass- 
age ;  it  may  have  eide-fratuing 
to  match  the  door  when  the 
width  of  the  passage  is  more 
than  the  width  of  the  door,  as 
illustj^ted  in  Fig,  691  ;  or,  as 
in  the  case  of  public  buildings, 
it  may  consist  of  a  pair  of  fold- 
ing or  swing  doors  with  fixed 
sidelights  and  a  fanlight  above. 
The  design,  as  well  as  the  treat- 
ment of  the  framing,  of  such 
doors  varies  considerably,  and 
is  often  of  an  ornamental  character.  Fig.  687  shows  a  pair  of 
swing  doors  with  Used  sidelights  and  fanlight ;  they  are  suitable 
for  the  entrance  to  a  school,  bank,  hotel,  or  similar  building 
having  a  wide  entrance  hall. 

An  arrangement  of  vestibule  doors,  suitable  foi'  banks,  hotels, 
etc.,  is  shown  in  plan  in  Fig.  685.  The  doors  are  annnged  at 
right  angles  to  each  other,  and  revolve  around  a  vertical  axis 
like  a  turn-stile.  Curved  side  frames,  each  a  little  wider  than 
a  quarter  of  a  circle,  are  fixed  on  each  aide  of  the  doorway.  A 
suitable  width  for  the  doors  is  3'  6".  The  advantages  of  such 
an  arrangement  is  that  it  is  noiseless  and  draughtproof,  the 
latter  feature  being  obtained  by  having  an  india-rubber  tongue 
fixed  in  the  outer  edge  of  each  door.  The  doors  are  so  hung 
that  a]ternat«  doors  can  be  folded  back  against  the  adjacent 


BDd  stylo  of  a  Saab  Door. 


SiSiioorlrame 

IflTgnd  HoriMUtaJ  SeoUon. 
'tjsir  of  Folding  Doors  (Witt  Upper  PaneU  ot  0\i«b1  Vv,  B,ti  W"  '^ 


362       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


ones  (Fig.  686),  and  thus  give  an  uninterrupted  passage  when 
required. 

Other  Panelled  Framing. — Framework  filled  in  entirely 
with  wooden  panels,  or  with  wooden  panels  in  the  lower  part 
and  glass  in  the  upper  part,  is  also  required  in  the  fittings  for 
offices,  for  school  partitions,  and  for  screens  in  churches,  business 
premises,  etc.  The  arrangement  of  the  framing  is  similar  to 
that  of  doors,  and  the  same  terms  are  used  to  describe  the 
various  parts,  the  only  diifei-ence  being  the  proportions  of  height 
and  width ;  these  are,  of  course,  governed  by  special  require- 
ments. The  setting-out  of  panelled  framing  is  dealt  with  in 
Chap.  XVTI. 


FiQ.  esfj. 


Fia.  686. 


Plans  of  llevolving  Vestibule  Doors. 


Superior  Doors. — In  superior  work,  where  the  doors  and 
surrounding  framework  are  made  of  ornamental  hardwood,  it 
is  often  necessary  to  construct  a  door  which  shall  be  of  one 
kind  of  wood  on  one  side  of  the  door  and  an  entirely  different 
kind  on  the  other  side.  This  would  be  necessary,  for  example, 
with  a  door  opening  from  an  entrance  hall  fitted  entirely  with 
oak  into  a  room,  the  fittings  of  which  must  all  be  of  walnut 
or  mahogany.  Such  a  door  may  be  constructed  in  two  thick- 
nesses, each  of  the  respective  kind  of  wood,  and  each  of  a 
thickness  equal  to  one-half  of  that  of  the  finished  door.  The 
two  parts  are  then  secured  together  by  tapering  dovetailed 
keys,  and  the  edges  of  the  door  are  afterwards  veneered  to 
match  the  side  of  the  door  to  which  they  correspond.  Figs.  701 
to  703  give  details  of  this  kind  of  door. 


I       |l       |2       3       I*      |5      i6      |7      i8a« 

calc  of  Drawing  ■ —  - . 

f^JFj^^^-TJ-'-fri-    Wife 


HonjonLal  Section 

Fio.  C8S. 
'H  nnd  SmIiuub  of  a  lair  ol  3uperiot  BtAnLBco  Bw«b. 


364       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

Tlie  doors  of  cnpbOBrde,  and  similar  framiDg,  being  generallj 
smaller,  are  made  thinner  and  lighter  than  ordinary  duois. 
They  ai-e  aiTanged  either  aa  single  doors  or  as  a  pair  of  doon 
hung  folding,  according  to  their  width.  With  this  exception, 
the  constriictioa  and  treatment  of  the  framing  do  not  materially 
differ  from  those  already  described. 

A  ]lb  door  18  a  duor  arranged  in  the  side  of  a  wall  in  such  t, 
manner  tliat  it  is  not  readily  seen.    The  surface  of  such  a  door 


is  flush  with  the  wall  surface,  and  is  treated  in  the  same  way 
as  the  wall  of  the  room  Its  position  ean  only  be  detected  l>y 
a  careful  etaminatiun,  is  only  the  joints  between  the  edges  of 
the  door  ind  the  wall  are  visible. 

Door  Frames  — Thei-e  iiie  many  ways  of  fixing  doors.  An 
outer  door  foi  a  dwelling  house  has  generally  a  solid  woodan 
frame,  which  Rta  into  the  recess  formed  in  the  wall.  This 
frame  consists  of  two  uprights  named  ]ambi  and  a  ci'osn  pie<'e 
or  head  into  which  tte  iani\»  n,iB  xemmsA.      ti&  ite  door 


36<i 


A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


altuoat  iDvariably  opeus  inwards,  the  frame  ia  rebated  on  th« 
inner  aide  to  receive  the  doot  (Fig.  690).  The  door  frame  nwj 
either  be  built  in  aa  the  brickwork  proceeds,  or  it  may  be  aftw- 
wards  fixed  by  na  1  ng  t  to  woodfln  bricks  or  alipe  built  into  the 
wall ;  r  the  na  dk  n  ^y  he  to  wooden  plugs  driven  into  tlie 
joints  If  the  doo  waj  r  of  stone,  as  in  Fig.  695,  the  fnmm 
are  secured  bj  u  eann  of  ron  holdfasts  named  Bpllt-Ulli,  or  hj 
raB-txdtB  secu  ed  to  the  stone  by  lead  or  brimstone.    The  lower 


ends  of  the  jambs  may  be  secured  additionally  by  iron  dowels, 
which  fit  inU)  hoks  in  the  dooi-attp  ;  or  tliey  may  be  secured 
siinilaily  to  stone  door-blocks,  which  are  rebated  and  keep  the 
door  frame  seveiid  inches  above  the  steji. 

Tlie  doorway  is  often  higher  thiin  the  door,  and  a  cross-rail 
called  a  traneom  is  placed  across  the  doorway  at  tlie  height  of 
the  top  of  the  door.  Above  this  transcnu  is  a  window  called  a 
bjillgbt.  Tlie  fanlight  may  l>e  simply  a  slieet  of  glass  secured 
b_y  filleta  into  the  rebate  of  the  door  frame,  or  it  may  have 


SUPERIOR  PANELLETt  DOORS.  3B7 


Horjjorftal  Section 


1bule  Too™  with  Hldo-liglita. 


368      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

a  separate  fi-aiiie  hinged  to  the  door  frame  bo  that  it  cm 
be  opened  for  ventilation.  The  outer  ari'ia  of  the  door  frame 
maj  be  ohunftrea  (Fig.  684),  bMdtA  (Fig.  695),  or  mMildM 
(Fig    700) 

Linings  — The  dooi  frame  is  seldom  of  sufficient  thickae«Biif 
itself  to  come  flush  with  the  inside  face  of  the  wall,  but  ueuallj 
requires  to  be  supplemented  by  IltUnga,  i.e.  by  boards  about  an 
inch  thick  md  wide  enough  to  project  beyond  the  inner  aurfics 
of  the  nail  for  -i  distance  of  three  quarters  of  an  inch  (the  ueutl 
thickness  of  the  plu- 
ter).    The  liningBuv 
tongued  on  one  edge 
to  fit  into  a  groove  in 
the  door  frame,  and 
are  generally  ijA^rtd, 
that  is,  fitted  at  an 
oblique      angle,     as 
shown    in    Pig.  695. 
The    joint     between 
the    lining   and  &t 
plaster     is     covered 
with  a  mould,  named 
according  to  its  shape 
a    band     mould     or 
sin^e   arebltrav*,   or 
a   donUe-Owed  arehl- 
trara.  The  architrave 
d  Jami"Lm"iia!'  ^"'""*     ia    fixed   around   the 
in  aide    of    door    and 
o  give  a  finished  appearance  to  the  whole, 
eiy  thicl>   forming  a  deep  recess,  the  linings, 
instead  of  being  pluin,  wide  boards,  are  framed,  panelled,  and 
nioul  led  ti  match  the  door      Fig.  700  shows  a  horizontal  cross- 
section  throuj,h  one  side  of  a  doorway,  into  which  is  fitted  a 
d  .tr  ftdnie  with  a  panelled  ]amb-lining. 

InBide  Door  Frames  — Inside  doors  require  frames,  the 
width  of  which  IS  equal  tc  that  of  the  wall  plus  the  thickness 
of  the  plaster  on  both  aides.  They  are  fixed  to  wooden  fillets 
OP  to  plugs  much  as  outer  door  frames  are  fixed.  Fig.  696  is  a 
sketch  of  a  door  frame  for  a  half-brick -thick  wall.  Id  superior 
bujJdiDgs    having    thick    inside    w&Ub,   the   door    frames    are 


DoorFrame  5"X' 


— HuiiAintal  HecbioD  tl 


SUPERIOR  PANELLED  DOORS. 


370      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

panelled  and  moulded  to  match  the  door,  and  are  related 

generally  on  both  edgea  (Fig.  704). 
Grounds. — The    architraves    surrounding    an    opening  are 

nailed  to  the  lining,  or  where  possible  to  the  fiume.  In  the 
best  class  of  work, 
however,  it  is  unuJ 
not  to  fix  the  door 
frames  until  the  pla>- 
tering  is  SniBhed. 
Bough  wooden  batteoB 
or  gronnds,  of  thick- 
ness equal  to  that  of 
the  plaster,  are  fii«l 
to  the  walla  around  all 
door  and  window  open- 
ings. These  serve  aa 
a  guide  to  the  plas- 
terer, and  the  door 
frames  and  the  sur- 
rounding architraves 
are  secured  to  them. 
When  it  is  not  desir- 
able to  have  any  nail 
holes  visible  in  the 
finished  surfaces,  the 
door  frames  and  ai-chi- 
traves    are    fixed    hj 

The  fixing  of  the 
architraves  around 
such  a  doorway  affords 
a  good  example  of  flx- 
Ing  1)7  secret  scTewlng. 
The  mitres  of  the 
architrai-es  are  first  glued  and  secured  with  dovetail  keys  or 
slip  feathers.  Stout  screws  are  turned  into  the  grounds  about 
la'  ax>art,  being  left  bo  that  the  head  of  the  screw  projects  alwut 
half-an-inch  in  fnait  cit  the  i-urface.  On  the  back  aide  of  the 
architrave,  exactly  opposite  the  si^rew  heads,  small  holes — equal 
to  the  size  of  the  lAanh  of  the  screws — are  bored  ;  and  about 
tbree-qu&rters  of  an  inch  below  these,  larger  holes — of  size 


M.-Skotct  of  lower 


Tscr 


,Hole 


..Sc"*"" 


HINGES.  371 

equal  to  the  heads  of  the  screws— are  bored.    Each  einall  hole 

is  connected  to  the  large  one  adjacent  to  it  by  a  slot,  the  depth 

of  which  is  slightly  greater  than  the  projection  of  the  screws. 

The  ai'chitrave  is  fixed  by  placing  it  against  the  wall  with  the 

larger  holes  fitting  on  _ 

the  screws,  and  then 

carefully    driving    it 

down  so  that  theheada 

of   the    screws    Lwk 

into  the  fibres  behind     p'X, 

the  slots     By  placing 

the    screws    so    that     /, 

they  are  slightly  in 

clined    the  tendency 

IS  to  draw  the  archi 

trave    closer    to    the 

wall      Fig  705  shows 

theexplanatorvdetail 
The  above  remarks 

upon     door      frames, 

Lninga,     etc ,     apply 

especially  to  the  doors 

of  dwelling-houses.     Door  frames  for  warehouses,  workshops, 

o\itbuildings,  etc.,  do  not  as  a  rule  require  linings  or  architraves, 

a  small  fillet  being   nailed   int«   the  angle  between  the  door 

frame  and  the  wall  instead.     Vestibule  doors  are  often  hung  to 

swing  both  ways,  and  the  door  frames  have  a  hollow  rebate  or 
groove  in  the  middle  of  the  width 
of    the    frame,     to    receive    the 
rounded  edge  of  the   door  (Fig. 
\        Many    of     the    heavier 
Teehifige  kinds  of  fmnred  and  ledged  doors 

are    not    provided  with  wooden 
frames,  but  are  hung  with  bands 

and   gudgeons,   or  arranged   to   run   on   pulleys  as   described 

Hinges. — Te«  or  erou  garnet  hinges  (Fig.  706)  are  used  for 
the  commoner  kinds  of  ledged  doors.  They  are  screwed  on  the 
surface  of  the  door  and  frame. 

H  and  HL  hinges  (Figs.  707  and  70fi)  are  also  hinges,  used  tut 
special  parpoaea,  which  are  screwed  on  tbe  6vii:la.c6. 


372      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

Bntt  hinges  (Fig.  709)  are  used  for  framed  doors  generally, 
two  or  three  hinges  leing  used  for  each  door,  accordiog  to  iU 
size  and  weight.  UHuall;  one-half  of  the  hinge  is  let  into  the 
edge  of  the  door,  while  the  other  half  is  let  into  the  fnnte 
(Fig.  712).     When  the  arris  of  either  the  door  or  the  frame  la 


©I 


BiiU  hinge 
Fio.  T09. 


beaded,  it  is  desirable  to  have  the  "  knuckle "  of  the  hinge  in 
line  with  the  head.  In  this  case  the  hinge  is  let  in,  as  shown 
in  Fig.  711.  Butt  hinges  are  of  cost  iron,  wrought  iron,  steel, 
or  brans  ;  tbej  are  secured  b^  screws. 


Piling  Hlngn. 


BlBlns  bntt  hinges  (Fig  713  have  a  hel  cal  knuckle  }omt 
which  causes  the  dooi  to  r  se  upon  be  ng  opened  They  are 
generally  used  when  the  floor  s  reg  lar  and  a  door  hung 
with  ordinir^   butts  would  not  open  without  rubb  ng  on  the 

FroJectU^r  butt  hinges  (F  g  14)  a  e  used  when  the  door 
has  to  open  quite  back  and  t  lear  an  arch  trave  or  other 
/projection      The  method  of  fazing  ssloun  n  Fig  710 


HINGES. 


373 


Paxllament  hinges  (Fig.  715)  are  another  kind  of  hinge,  a 
little  stronger  than  projecting  butts.     They  are  used  for  the 


Fig.  713  —Rising  Butt  Hinge. 


Fig.  714.— Projecting  Butt  Hinge. 


same  purpose,  and  for  shutters — fixed  in  revealed  openings — 
which  are  required  to  open  clear  of  the  reveal. 

Pew  or  egg-Joint  hinges  (Fig.  716)  are  a  type  of  projecting 
hinge  used,  as  the  name  implies,  for  the  pew  doors  of  churches, 


Fio.  715. — Parliament  Hinge. 


Fig.  716. — Pew  or  Egg-joint  Hinge. 


etc.     The  projection  allows  the  door  to  fold  back  clear  of  any 
projecting  moulding. 

Back-flap  hinges  (Fig.  717)  are  somewhat  similar  to  -^yo^^c^yci^ 
butts,  but  are  lighter  in  make.  Whereas  "bMUYiiti^ei^  «jc^  ^^w^^-sn^^I 


374      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

Dcrewed  on  the  edge  of  the  door  or  framing,  the  back-flap  biDgS 
ia  usually  screwed  on  the  surface.  Boxed  window-ahutten 
with  rebated  jointa  (Fig.  792),  are  usually  hung  together  with 
back.flap   hinges.      These   biDges   are   also   used  for    hingeing 


o    o   -  o    c 

o    c  r  o    ® 


— Bai:lc-finp  Hinge. 


HoUnal  Spring  Hinge. 


together  the  framing  required  to  fold  round  an  angle.    "When 
the  joint  is  arranged  as  in  Fig.  793,  it  is  called  a  rule  Joint 

Spring  hlngeB. ^Spring  hinges  are  often  used  when  it  is 
desirable  to  have  a  self-closing  door.  The  helical  binge  (Fig. 
718)  affords  a  good  exaniple  of  a  spring  hinge  for  screwing  on 


Fiu.  Tie.— Spring  Htngo. 


the  edge  of  a  door.  One  only  of  the  hinges  on  each  door 
contains  a  spring,  the  other  being  known  as  a  WoTiX-  hinffe. 
Such  hinges  are  single  or  double  according  to  whether  the  door 
closes  into  a  rebate  or  Hwings  both  ways.  Other  types  of  spring 
hinges,  especially  app\ica.b\e  ior  leatiWXa  ioota  '«\v\dQ.  ^.t^  *« 


BANDS  AND  GUDGEONS. 


375 


swing  both  ways,  are  those  which  are  let  into  the  floor  and 
contain  mechanism  in  the  shape  of  springs  which  are  acted 
upon  when  the  door  is  opened  (Fig.  719).  A.  shoe  (Fig.  720;  is 
fitted  on  the  bottom  corner  of  the  door  ;  this  fits  on  a  pin 
which  acts  upon  the  springs  in  the  box.  A  centre-pin  holds 
the  upper  end  of  the  door  in  position. 

Bands  and  gudgeons. — For  the  heavier  kinds  of  framed, 
ledged,  and  braced  doors,  stronger  hinges  are  required  than 
those    above    described.      These    hinges,   which   are  made  of 


o  Band  <> 


Gudgeonj 


Pio.  721. 


> 


.  Gudgeon 


Fia.  722. 


Gudgeon 


Fig.  723. 


Fig.  724. 


G 


Fio.  725. 


Types  of  Baud  and  Oudgeoii. 


wrought  iron,  are  known  as  bands  and  gudgeons  or  as  hook  and 
eye  hinges.  The  gudgeon  has  a  projecting  pin  upon  which  the 
band  swivels.  This  allows  of  the  door  upon  which  the  bands 
are  screwed  or  bolted  being  easily  detached  from  its  swinging 
position.  The  gudgeons  may  be  so  made  that  they  can  be 
screwed  to  the  frame  (Fig.  722),  although  in  the  heavier 
kinds  of  doors  the  frame  is  dispensed  with,  and  the  gudgeons 
are  so  shaped  that  they  can  be  fixed  securely  by  lead  or 
brimstone  to  large  gudgeon  stones  built  into  the  wall.  Figs. 
721  and  724  show  two  different  shapes  of  gudgeons  for  stones. 
The  h&nds  may  he  as  single  straps  bolted  to  oiife  «v\^  <A  ^^ 


376      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

door  (Fig.  721),  or  they  may  be  made  to  clip  the  door, 
whicli  case  they  will  be  shaped  as  shown  in  Figs.  723 
They  may  be  pkin,  or  they  may  he  of  an  omamental  shape 
(Fig.  653).  The  si/e  of  such  hingeti  difTera  widely  and  dependa 
upon  the  aize  and  weight  of  the  door. 

Sliding  Doors. ^When  the  door  is  a  very  large  one,  or  where 
apace  will   not   allow   conveniently  of  a  hinged  door  to  open 


.1 


radially,  the  door  may  be  made  to  slide  by  means  of  pulleys 
running  upon  an  iion  bar.  The  pulleys  may  be  placed  either 
at  the  top  or  at  the  bottom  of  the  door.  The  door  may  slide 
in  a  slot  constructed  in  the  middle  of  the  thiekness  of  the  wall, 
or  it  may  slide  on  the  outside  surface,  or  be  arranged  to  slide 
against  the  inner  face  of  the  wall  as  is  most  convenient.  Fig, 
649  shows  a  door  fitted  with  pulleys  at  the  upper  end. 

FaBteningS. — The  fastenings  for  a  door  comprise  Uminb 
latdies,  rim  latcbes,  bars,  bolti,  locks,  etc.  To  enumerate  these 
in  detaii  would  be  beyond  the  Bcope  <^  ftiw  \wuY,  e*  \,\ie,-3  -j«c^ 


DOOR  FASTENINGS.  377 

considerably.  It  should  be  remembered,  however,  that  careful 
selection  of  the  door-fastenings  is  necessary  to  obtain  good 
results.  Figs.  726  to  733  illustrate  different  locks,  latches,  and 
other  fastenings  with  their  distinctive  names  appended.  It 
■will  be  noticed  that  a  rim  latch  differs  from  a  lock  in  that  it 
is  self-fastening,  and  is  released  by  turning 
the  knob.  A  rim  lock  is  a  latch  and  lock 
combined  in  the  same  case.  The  best  locks 
are  fitted  with  levers.  These  levers  are  kept 
in    position    by   springs,   and   require   to   be 

raised  to  different  heights  to  allow  the  bolt 

to  slide.      The  more   levers  a  lock  contains, 

the   more  difficult  it  is  to  open  it  with  any 

key  which  has  not  been  fitted  to  it.     Many     ^''''  ^Li^^"""^^ 

locks  contain  pivoted  weights  instead  of  levers. 

It  has  already  been  mentioned  that  a  mortise  lock  is  so  called 

because  it  is  fixed  into  a  mortise  made  in  the  edge  of  the  door. 

Mortise  latches  and  locks  are  always  used  in  superior  work. 


Summary. 

Doors  are  classed  as  ledgedy  ledged  and  braced,  framed  ledged  and 
braced  J  and  panelled.  The  two  last-named  consist  of  frames  filled 
in  with  thinner  battens  and  panels  respectively. 

The  mortise  and  tenon  joint  is  used  in  the  construction  of  framed 
doors.  The  tenon  is  bare-facedy  haunched,  stump,  or  double,  accord- 
ing to  its  position  in  the  door. 

The  battens  of  "framed  and  ledged"  and  "ledged"  doors  have 
either  tongued  avd  grooved,  ploughed  and  tougued,  or  rebated  joints. 
The  edge  joints  of  the  battens  are  beaded  or  V-jointed, 

The  firame  of  a  door  consists  of  styles,  rails,  braces  (in  ledged  and 
braced  doors),  and  murUins  (in  panelled  doors). 

Panelled  firaming  is  finished  square  and  flat,  stop-chamfered, 
single  movlded,  bolection  madded,  bead  flush,  bead  butt,  or  raised 
[fielded). 

Foldin^r  doors  are  used  for  wide  doorways. 

A  donble  margin  door  is  one  door  made  to  imitate  folding  doors. 

Sash  doors  have  the  upper  panels  of  glass. 

The  joints  and  general  treatment  of  panelled  doors  are  also 
appUcable  to  other  kinds  of  panelled  framing. 

Door  firames. — Outer  doors  are  hung  to  solid  rebated  It^tcv^'^  ^■iL'b^ 
in  reveals  in  the  wall.     Linings  are  reqwired  wYveiv  Wve  doot  Vc%.\!aa 


378       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

is  not  as  wide  as  the  recess.  Inside  door  frames  must  be  wider,  by 
the  thickness  of  the  plaster,  than  the  thickness  of  the  waU.  Archi- 
traves surround  the  inner  sides  of  outer  doorways  and  both  sides  of 
inner  doorways.  Qrownds  fastened  to  the  wall  by  wooden  plugs  are 
necessary  for  securing  wide  architraves. 

Hinges. — Tee  hinges,  hvtt  hinges,  spring  hinges,  and  hands  aiid 
gudgeons  are  commonly  used  for  hanging  doors. 

Heavy  doors  are  often  hung  to  large  gudgeon-stones  by  means  of 
bands  and  gudgeons,  or  are  constructed  to  slide  with  pulleys. 
Wooden  frames  are  then  not  required. 


Questions  on  Chapter  Xm. 

1.  Give  the  ordinary  dimensions  of  various  kinds  of  door,  with 
the  sizes  of  the  following  parts  of  a  common  four-panel  door: 
styles,  top  rail,  middle  rail,  bottom  rail,  muntin ;  also  state  the 
proper  height  of  the  middle  rail  to  suit  the  handle  or  lock.  (C.  and 
G.  Ord.,  1894.) 

2.  Draw  in  isometrical  projection,  quarter  full  size,  the  mortise 
and  tenon  to  the  bottom  rail  of  a  2-inch  door,  the  parts  being 
separated.     (C.  and  G.  Prel.,  1897.) 

3.  Make  detailed  drawings  of  the  following  : 

(1)  Framing  moulded  on  the  solid,  with  raised  panel. 

(2)  Bead  and  butt  panel. 

(3)  Bead  and  flush  panel. 

(4)  An  arrangement  for  fixing  moulding  in  squared  framing 

panelled.     No  nails  or  screws  are  to  be  visible  when  the 
work  is  finished.     (C.  and  G.  Ord.,  1902.) 

4.  Make  an  elevation  and  sections  of  a  2-in.  framed,  braced,  and 
battened  door,  3  ft.  3  in.  by  6  ft.  6  in. ;  show  all  construction  by 
dotted  lines.  Scale  1^  in.  to  the  foot.  State  in  what  situation 
such  a  door  would  bo  most  suitable.     (C.  and  G.  Ord.,  1901.) 

5.  Draw  plan  and  elevation  to  J  in.  scale  of  framed,  ledged,  and 
braced  door,  in  two  heights,  with  fanlight  over  and  solid  fir 
wrought,  rebated  and  beaded  frame  in  opening  4  ft.  by  9  ft.  (C.  and 
G.  Ord.,  1897.) 

6.  Make  the  elevation  of  rather  more  than  half  of  a  six-panelled 
door,  7  ft.  high  and  3  ft.  2~in.  wide  ;  and  a  vertical  section,  scale 
1  in.  to  the  foot.  All  the  parts  should  be  fully  dimensioned. 
Make  to  scale  ^  full  size  a  detailed  section  through  the  panel  and 

moulding.     (C.  and  G.  Ord.,  1»^^.^ 


QUESTIONS  ON  CHAPTER  XIII.  379 

7.  Make  isometric  drawings  of  the  joint  at  the  lock-rail  of  the 
loor  in  the  preceding  question  (6),  and  also  of  the  joint  at  the 
x)ttom  rail  of  the  door,  with  double  tenons.    (C.  and  G.  Ord.,  1898.) 

8.  Make  elevation,  horizontal,  and  vertical  sections  of  a  2  in. 
5-panelled  door,  7  ft.  high  and  3  ft.  5  in.  wide,  with  framed  jamb 
inings  and  raised  panels,  moulded  on  the  solid,  grounds  and 
architraves.  All  construction  to  be  shown  in  dotted  lines.  The 
thickness  of  the  wall  is  27  in. ,  Describe  how  you  would  make  and 
fix  this  door  and  fittings,  presuming  all  to  be  first-class  work. 
(C.  andG.  Hon.,  1902.) 

9.  Give  detail  drawings,  and  describe  how  you  would  make  and 
fix  a  set  of  plain  jamb  linings,  grounds  and  architraves  for  an 
internal  doorway.  Thickness  of  wall,  14  in.  (C.  and  G.  Ord., 
1904.) 

10.  Draw  plan  and  elevation  to  J  in.  scale  of  a  pair  of  2J  in. 
folding  doors,  each  leaf  five-panel  bolection  moulded,  with  raised 
(or  fielded)  panels.  Size  of  opening  6  ft.  by  7  ft.  6  in.  (C.  and  G. 
Ord.,  1897.) 

11.  Show  the  linings  and  finishings,  with  details  of  grounds  and 
backings,  necessary  to  the  above  door  (Q.  10)  in  a  14  in.  wall. 
(C.  andG.  Ord.,  1897.) 

12.  Make  detailed  drawing,  scale  J  full  size,  of  the  joints  of  a 
2  in.  sash  door,  6  ft.  6  in.  high  and  3  ft.  wide.  The  styles 
are  to  be  diminished,  and  one  prepared  for  a  lock.  The  upper 
portion  of  the  door  is  to  be  moulded  and  rebated  for  glass.  (C.  and 
G.  Ord.,  1902.) 

13.  A  door,  such  as  that  referred  to  in  the  foregoing  question,  is 
to  be  hung  in  a  solid  frame  3^  in.  by  4^  in.  Make  a  drawing  of 
this  frame  and  describe  how  you  would  make  it  in  a  shop  without 
machinery.     (C.  and  G.  Ord. ,  1902. ) 

14.  Draw  to  a  scale  of  one  inch  to  a  foot,  plan,  section  and 
elevation  of  a  pair  of  2^  in.  swing  doors,  5  ft.  6  in.  wide,  upper 
part  framed  for  glass,  bolection  moulded  below,  and  hung  to  solid 
frame.     (C.  and  G.  Ord.,  1895.) 

15.  Draw  rather  more  than  half  the  horizontal  section  through  an 
internal  doorway,  wall  1  ft.  6  in.  thick.  Show  framed  jamb- 
linings,  grounds  and  architrave,  and  the  method  of  fixing  same. 
The  door  to  be  2  in.  thick,  with  raised  panels  and  mouldings. 
Scale  3  in.  to  1  ft.     (C.  and  G.  Ord.,  1900. ) 

16.  A  front  doorway  to  a  mansion  is  7  ft.  6  in.  wide  and  9  ft. 
6  in.  high.     Design  a  frame  and  door  for  this  o^^wiiv^.    T\ve,  ^Q«t 
is  required  to  be  double  margined  with  a  ianWgJat  over  \V..    '^^i^^^^ 


380       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

rather  more  than  half  elevation,  and  the  necessary  sections.     All 
details  are  to  be  shown  by  dotted  lines.     (C.  and  G.  Hon.,  1901.) 

17.  A  screen  15  ft.  wide  and  10  ft.  high  is  required  for  a  public 
office.  It  is  to  be  fitted  with  a  door  3  ft.  by  6  ft.  9  in. ,  and  to  be 
made  of  mahogany,  and  well  finished.  Draw  as  much  of  the 
elevation  as  is  necessary  to  show  the  construction,  and  give  details. 
Describe  the  process  of  manufacture  in  a  good  workshop  well 
provided  with  machinery.     (C.  and  G.  Hon.,  1900.) 


CHAPTEE  XIV. 
WINDOWS. 

Size  and  Position. — The  sizes  and  positions  of  window 
openings  are  influenced  by  the  size  of  the  rooms,  and  the 
purposes  for  which  the  building  is  used.  For  the  sake  of 
ventilation,  and  also  to  secure  good  lighting,  the  windows 
should  be  placed  at  as  great  a  height  as  the  construction  of  the 
room  will  allow.  In  dwelling-houses  the  height  of  the  sill  is 
usually  about  2'  6"  above  the  inside  floor  level. 

Construction. — The  framework  holding  the  glass  of  the 
window  m.ay  be  fixed  or  movable.  It  must  be  so  prepared  that  ( 
the  glass  can  be  replaced  easily  when  necessary.  In  ware- 
houses, workshops,  and  similar  buildings,  the  frames  holding 
the  glass  are  often  fixed  as  &at  sheets  (Fig.  734).  As  however, 
this  arrangement  aflbrds  no  means  of  ventilation,  it  is  more 
usual  to  have,  the  glass  fixed  in  lighter  frames  called  sashes.  If 
the  sashes  are  hung  to  solid  rebated  frames,  and  open  as  doors 
do,  the  windows  are  called  casement  sashes.  If  they  slide 
vertically  and  are  balanced  by  weights  or  by  each  other,  the 
window  is  a  sash  and  firame  window.  Other  methods  of  arrang- 
ing sashes,  either  hinged,  pivoted,  or  made  to  slide  past  each 
other,  are  described  in  detail  later. 

Sashes. — The  terms  used  for  the  various  parts  of  sashes  and 
fast  sheets  are  somewhat  similar  to  those  employed  in  describing 
doors.  Thus,  the  styles  are  the  outer  uprights,  and  the  rails 
are  the  main  horizontal  cross-pieces :  top  railsy  meeting  rails, 
and  bottom  rails  being  distinguished.  Any  intermediate 
Jnembers,  whether  vertical  or  horizontal,  are  named  bars. 

Sashes  are  from  1 J  to  3  inches  thick.  The  inner  edge  of  the 
outer  face  is  rehated  to  receive  the  glass.    TYie  iioier  i^ci^  V^ViW. 


382       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


either  square,  chamfered,  or  moulded ;   two  common  forms  of 
moulding  are  lamh^s-tongue  (Fig.   736)  and   ovolo  (Fig.  737). 


Elevation  ofaf/xed  W/nc/ow Frame    ^/^^^ 


HortzontalSecUon' 

Fig.  734. 

The  size  of  the  rebate  is  indicated  in  Fig.  735 ;  it  varies  with 
the  thickness  of  the  sash,  its  depth  being  always  a  little  more 


mast 


Fig.  735. 


Bebaba 
—  for 
Glass 


Fig.  736.  Fio.  737. 

Alternative  Sections  of  Sash  Framing. 


than  one-third  this  thickness.  The  width  of  the  rebate  varies 
from  a  quarter  of  an  inch  to  half  an  inch,  and  the  mould  is 
usually  sunk  the  same  depth  as  the  rebate.  This  last  fact  is  of 
BomQ  importance,  as  it  affects  the  shoulder  lines  ;    and  with 


:t 


* 


WINDOWS.  S83 

hand  work  it  influences  the  amount  of  labour  in  the  making  of 
the  aaahea. 

Aa  little  material  as  possible  is  used  in  the  sashes,  in  order 
that  the  light  shall  not  be  interfered  with.  In  general,  the 
styles  and  top  rail  are  square  in  section  before  being  rebated 
and  moulded.  In  casement  sashes, 
however,  it  is  often  advisable  to 
have  the  outer  styles  a  little  wider 
than  the  thickness,  especially  when 
they  are  tongued  into  the  frame. 
The  width  of  the  bottom  rail  is 
from  one  and  a  half  to  twice  the 
thickness  of  the  sash.  Sash  bars, 
which  require  rebating  and  mould 
ing  on  both  aides,  should  be  as 
narrow  aa  possible,  in  oi'der  not  to 
interrupt  the  light.  They  are 
usually  from  five-eighths  of  an  inch 
to  one  and  a  quai'ter  inches  wide. 

Joints  of  Sashes. — The  sashes  are 
framed  together  by  means  of  the 
mortise  and  tenon  Joint  (Fig.  739). 
The  remarks  made  on  p.  348  respect- 
ing the  proportions  of  the  thickness 
and  width  of  tenons,  haunch  ed 
tenons,  etc.,  are  to  a  large  extent 
applicable  here  also.  Hardwood 
cross-tongues  are  sometimes  inserted 
to  strengthen  the  joints  (Fig.  302), 
while  thick  sashes  should  have 
donble  tenoni  (;fig,  7S2).  The  best 
joint  for  connecting  sash  bars  is 
shown  in  Fig.  740 ;  this  method  is 
known  as  halTin?.      An   alternative 

to  halving  in  sash  bars  is  to  arrange  that  the  bar  which  is 
subjected  to  the  greater  stress— as  for  example,  the  vertical 
bars  in  sliding  sashes,  and  the  horizontal  bars  in  hinged 
casement  saahea— shall  be  continuous  ;  this  continuous  bar  is 
mortised  to  receive  the  other,  which  is  scribed,  i.e.,  cut  to  fit 
the  first,  and  on  which  the  short  tenons  are  left.  This  method 
is  called  ttaaitag  the  Muh  bars,  and  is  illaabcKtM  \ii  Y\%.  1U. 


384       A  MANUAL  OF  CARPENTRY  AND  JOINERY.    . 

Casement  Windows. — Casement  windows  may  be  hinged  in 
such  a  manner  that  they  open  either  inwards  or  outwards. 
They  may  consist  either  of  one  sash,  or  of  folding  sashes,  and 
are  hung  with  butt  hinges  to  solid  rebated  frames.  Thede 
firames  consist  of  jambs,  head,  and  sill.  The  head  and  sill  "run 
through,"  and  are  mortised  near  the  ends  to  receive  tenons 
formed  on  the  ends  of  the  jambs.  The  upper  surface  of  the 
sill  is  weathered  to  throw  off  rain  water.  Casement  windows 
which  reach  to  the  floor  are  usually  called  French  casementB. 
Their  sashes  require  an  extra  depth  of  bottom  rail. 

Casement  Sashes  opening  Inwards.— Figs.  742  to  745  show 
the  elevation  and  vertical  and  horizontal  sections,  of  a 
window  opening  in  a   14"  brick  wall  fitted  with  a  casement 


Sask  bars  halved^ 
together. 


Fig.  740. 


-wWimortiA' 
andtenorv 


Pig.  741. 


r  window  having  folding  sashes  to  open  inwards.  In  this  class 
of  window  the  frame  is  rebated  for  the  sashes  on  the  inner  side. 
Each  sash  has,  on  the  outer  edge  of  the  outer  style,  a  semi- 
circular tongue,  which  fits  into  a  corresponding  groove  in  the 
jamb  of  the  frame.  This  tongue  renders  the  vertical  joint 
between  the  sash  and  frame  more  likely  to  be  .weather  proof  ; 
it  is  to  provide  for  the  tongue  that  the  extra  width  of  style 
already  referred  to  is  necessary.  The  tongue,  however,  is 
often  omitted,  as  in  Fig.  746.  It  will  be  seen  readily  that, 
if  the  sash  were  in  one  width,  it  would  be  impossible  to 
have  a  tongue  on  more  than  one  edge  of  it.  With  casement 
sashes  opening  inwards,  the  greatest  difficulty  is  found, 
however,  in  making  a  water-tight  joint  between  the  bottom 
rail  of  the  sash  and  the  sill  of  the  frame.  Figs.  746  and 
747  show  two  methods  by  which  this  may  be  accomplished. 
An  essential  feature  of  all  these  sashes  is  a  small  groove  or 


386       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

throating:  on  the  under  edge  of  the  bottora  rail ;  this 
prevents  the  water  from  getting  through.  The  groove  in  the 
rebate  of  the  sill  (Fig.  747)  is  provided  to  collect  any  water 
that  may  drive  through  the  joint.  This  water  escapes  through 
the  hole  bored  in  the  centre  of  the  sill. 

When  casement  sashes  are  hung  after  the  manner  of  folding 
doors,  the  vertical  joint  between  the  meeting  styles  is  rebated. 
Alternative  methods  of  rebating  are  shown  in  Figs.  748  and  749. 
Fig.  749  is  known  as  a  hook  Joint  and  is  the  better  one. 

Casement  Sashes  opening  Outwards.— These  are  more 
easily  made  weather  proof  than  inward-opening  sashes.  The 
chief  objections  to  their  adoption  are  that  they  are  not  easily 
accessible  for  cleaning  the  outside,  especially  in  upper  rooms, 
and  that  they  are  also  liable,  when  left  open,  to  be  damaged  by 
high  winds  and  to  let  in  the  rain  during  a  storm.  Fig.  750  is  a 
sketch  of  one  corner  of  such  a  window.  It  will  be  noticed  that 
these  frames,  like  door  frames,  have  the  exposed  arrises  moulded 
in  various  ways,  and  that  the  sashes  may  either  be  hung  flush 
with  one  face  of  the  frame,  as  in  Figs.  745  and  746,  or  fit 
in  the  thickness  of  the  frame  (Figs.  747  and  750).  The  sill  in 
Fig.  749  is  shown  to  be  double  sunk,  i.e.  to  have  the  upper 
surface — upon  which  the  bottom  rail  of  the  sash  fits — i-ebated 
with  two  slopes  (weatherings). 

Other  Hinged  Sashes.  —  Various  different  methods  of 
arranging — in  solid  rebated  frames — sashes  which  can  be  opened 
for  purposes  of  ventilation,  etc.,  though  they  may  be  in  positions 
difficult  of  access,  are  shown  in  Figs.  751  to  754.  Fig.  751  is  the 
elevation  of  a  window,  the  lower  sash  of  which  is  fixed  in  the 
frame,  the  upper  sash  being  hinged  on  the  bottom  rail  to  open 
inwards.  The  bottom  rail  is  rebated  to  fit  the  transom  (the 
intermediate  horizontal  member  of  the  window  fi^me) ;  the 
upper  side  of  the  transom  is  weathered  and  double  sunk,  as 
shown  in  enlarged  section  (Fig.  752).  Such  an  arrangement  is 
also  applicable  to  a  fanlight  over  a  door,  where  the  sash  may 
be  made  conveniently  to  fit  into  the  rebate  of  the  door-frame. 
Fig.  754  is  a  section  through  a  similar  window  with  the  sash 
hung  on  the  top  rail.  A  sash  so  hung  must  of  necessity  open 
outwards,  to  keep  out  the  rain,  etc. 

Pivoted  or  Swing  Sash.— Another  method  of  arranging  the 

sash  is  shown  in  section  in  Fig.  753.     Here  the  sash  swings  on 

iroD  pins  or  pivots  (Fig.  797").    TVie  -^xNot^  ^a:^  Y^wied  a  little 


388       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

above  the  middle  of  the  sash,  so  that  the  lower  part  (whidi 
alwiiys  swings  outwards)  is  heavier  than  the  upper.  Thia 
facilitates  the  ulosing  of  the  window  The  rebate  on  the  lower 
part  of  the  frame  muat  of  necessity  be  inside,  and  the  rebate  cJ 
the  upper  part  muat  l>e  outside.     To  secure  uniformity  of 


with  Upper  Sish  to  oi»ii.  OppBTSii^hinggd  SashteSK/UfffO^ 

to  operu  inwcw^A. 


AlteraKtive  aQctfone  through  Upper  8uh  of  Fig.  TSl 

appearance,  a  bead  is  run  round  the  sash  along  both  styles  and 
top  lail,  and  on  each  side  of  the  sash.  It  is  therefore  necessary 
to  have  the  lower  pait  of  the  outside  bead,  and  the  upper  part 
of  the  inside  l.iead,/:rerf  to  the  laih.  These  points  will  be  clear 
from  a  careful  inspection  of  Fig.  Ira.  Occasionally  the  styles  of 
the  sash  and  the  jambs  of  the  frame  are  rebated  "out  of  the 
solid."    This,  however,  involves  increased  labour,  and  is  seldom 


^^^  SASH  AND  FRAME   WINDOWS. 

Sashes  Slidine  Horizontallr.  —It  is  often  necessai'y  to  bave 
two  Bashes  fitted  iiiUi  a  solid  fmme  so  that  one  or  both  of  the 
sisbea  may  sUde  horizonUilly.  The  sashes  are  constructed  in 
the  ordinary  way,  and  are  often  provided  with  metal  shoes  or 
pulleys  at  the  bottom  cornera,  to  enable  them  to  elide  smoothly. 
Figs.  755  to  757  are  the  elevatitm  and  two  sections  of  this  type 
of  window  arranged  for  lioth  the  sashes  to  slide.     If  only  one 

Bilsh  slides,  and  the  other  sash  is  fixed,  the  

window  is  sometimes  called  a  VoikBlUre 
tigIA      Such  wiudoWH   are   often  used  as  Hinqi, 

basement  windows.  The  glass  doors  of 
show-cases  in  shops  are  commouly  con- 
structed to  slide  in  this  manner.  ,'/ 

Sash  and  Frame  Window.— In  this  ,'//, 

cIrtHa  of  window,  whidi  is  by  far  the  moat  /[''// 

common,  liecause  it  is  easily  made  weather-  ''-i' 

pi'oof,  there  are  two  sMiBfl,  which  slide 
pa«t  each  other  in  vertical  grooves,  and 
are  usually  balanced  by  iron  or  leaden 
wel£bta.  Aa  will  be  seen  from  Fig.  760 
the  frames  form  cases  or  boxes  in  which 
the  weights   are   fuspenriisd.        Tliey   are  ■ 

hence   called   caud   &ames.     Pulley   stylas  ^ 

(Fig.    765)    take    the   place   of   the    solid  "§ 

rebated  jambs  of  casement  windows.     The  ^ 

pulley  styles,  outstde  and  InaUte  Ilnlogi, 
and  Hack  lining  (Fig.  760J  together  form 
a  bos  which  is  subdivided  by  a  vertical 
parting;  slip  suspended  as  shown  in  Fig. 
7(J0.  Ill  superior  window  frames  of  this 
kind,  the  pulley  styles  and  linines  are    i.£'r:j"?^'~^i'''°^ ^^'j 

'  y         J        J  "  nmgerl  to  open  mitwdrda. 

tongued  and  gi-ooved  together  as  shown 

in  Fig.  761.  In  commoner  work  the  tongues  and  grooves 
are  often  omitted.  The  frame  must  be  so  constructed  that  the 
saslies  can  be  removed  easily  for  the  purpose  of  replacing 
broken  sash-lines.  To  enable  this  to  be  done,  the  edge  of  the 
inside  lining  is  either  made  flush  with  the  face  of  the  pulley 
style  (Fig.  761),  or  it  ia  rebated  slightly  as  shown  in  Fig.  774. 


The  edge  of  the  oi 
three-quarters  of  an  : 
>  form  a  rebate  agai 


ide  lining  projects  foi'  a  distance  of  about 
nch  beyond  the  face  of  the  pulley  Rtyle, 
'Dst  which  the  outer  (u^'pet'^  eaia^i  %\\4.e». 


390      A  MANUAL  OP  CABPENTEY  AND  JOINERY. 

The  outer  aaah  is  kept  in  poBition  by  the  paiUiv  l»th  (Fig.  TfiO) 
which  fits  into  a  gmove  in  the  pulley  tityle.  The  groove  fm 
the  inner  (loner)  Bash  is  formed  by  the  parting  lath  and  a  ataf 
bead  or  rtop  bead  which  ia  secured  by  ecrewa.  The  staff  bead 
oil  the  sill  ia  often  made  from  two  to  three  ioches  deep,  W 
allow  the  lower  saab  to  be  raised  aufflciently  for  ventilatiuo 


Horizonldl  SecHon. 


Dstails  of  n  Windon 


xlth  aaihoa  sliding  h( 


nil  tally. 


at  the  ii^ceUDg  rails  without  causing  a  di'aiight  at  the  bottom 
(Fig.  791). 

A  vertical  section  through  the  head  of  the  frame  is  similar 
to  a  horizontal  section  acniKs  the  pulley  style,  eicept  that  the 
back  lining  and  parting  slip  are  of  course  absent  (Fig.  759). 

The  sill  of  the  frame  ia  solid  and  weathered,  and  should 
always  be  of  hardwood,  preferably  oak  or  teak.  The  rHI 
has  a  width  equal  to  the  full  thicknexs  of  the  frame.  When 
tie  weathering  has  two  Btepp\o?p,  \\-  \a  V.\w«\x  3.11  a.  doutda 


SASH  AND  FRAME  WINDOWS. 


Details  u!  a  8aa!i  and  Frame  Window. 


392      A  MANUAL  OF  CARPENTEY  AND  JOINERY. 

■unk  bUL  An  alternative  to  the  plan  of  having  the  width  ot  the 
Hill  the  full  thickneas  of  the  frame,  ia  to  aiTUDge  it  so  th&t  tbe 
outside  edge  ia  flush  with  the  outside  face  of  the  bottom  sash, 
as  ahowD  in  Fig.  762.  With  a  till  arranged  in  thia  manner,  and 
double  sunk,  there  is  lesa  danger  of  water  driving  through  the 
joint  between  the  saah  and  the  aill  than  with  a  Bill  the  fu" 
thickueBs  of  the  frame.  In  order  to  render  watertight  tlie 
joint  between  the  wooden  and  stone  sills  of  window  franiea,  * 
metal  tongue  is  often  fixed  into  corresponding  grooves  cut  int" 
the  under  side  of  the  wooden  sill  and  the  upper  surface  ot  tt** 
atone  aill.     A  rebated  joi*' 


betwi 


o  the  t' 


aills  H( 


,    t»^ 


HttalTSjlHiiii 


^ 


the   same   purpoae  t 
metal  tongue. 

Fig.  766  ahowB  tt^* 
methods  of  fixing  the  puU^^^'. 
style  into  the  head  and  s*:--", 
I espectively  when  thewidC;^^--^ 
of  the  sill  IB  equal  to  tl^^** 
full  thicknesB  of  the  fram^^^ 
The  pulleTi  on  which  th.  * 
aaah  linea  run — sash  or  axl  ^ 
pulleys  (Fig  800)— are  fixec^^ 
lu  mortiaea  near  the  uppe:^' 
nd  of  the  pulley  styles- 
P  y  J        I  I      It  Ls  alao  necessary  to  hav^ 

otai  t         ndiv  a    lemovable    piece   in   the 

lower  part  of  each  pulley 
style,  to  all  jw  of  access  to  the  weights  This  piece  la  named 
the  pocket  piece  It  ma;  be  cut  ds  allow  n  in  Fig  /64  its 
position  ia  then  behind  the  lowei  aaah  and  it  is  hidden  from 
view  when  the  window  la  cloaed  Or  the  po<,ket  piece  may  be 
in  the  middle  of  the  pulley  atyle  aa  ahowu  in  Fig  63  the 
vertical  jomta  between  the  pocket  piece  and  the  pulley  atyle  are 
then  V-sh^ped  to  pieient  damage  to  the  paint  tn  case  of 
reiuoval. 

Sashes. ^Tlie  only  difference  between  the  joints  of  sliding 
sashes  and  those  of  the  casement  saahes  already  described  ia  in 
the  construction  of  the  meeting  rails.  Each  of  the  meeting  rails 
is  made  thicker  than  the  sash  to  the  extent  of  the  thickness  of 
t/iepai'tinglath;  otherwise  tiiBrewoa.\'l.\)e  a  ft^actlietween  them 


SASH  AND  FBAME  \ 


394      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


equal  to  the  thickness  of  tke  parting  lath.    The  joint  between 
them  may  be  rebated  (Fig.  759)  or  eplayed  (Fig.  ■"   "        ~ 


angle  joints  between  the  ends  of  the  saah  styles  H[id  the  meeting 
rails  are  often  dovetailed  as  shown  in  Fig.  768.  They  ar«, 
however,  stronger  if  tlie  atjtea  ate  BvaAe  a.  UuVe  \on?,er,  the 


SASH  AND  FRAME  WINDOWS. 


}>rojecting  part  being  moulded,  and  mortise  snd  tenon  joiiila 
U3ed  iia  shown  in  Figs.  767  and  769.     The  projecting  auda  of  the 


Ifcylea  are  called  jogslea  ;  they  assist  in   enabling   the   iiasliee, 
'mBpecisUf  ia  wide  windows,  to  alide  tuqtc  IteftX^.    'W\iOTi,'aa\(i 


396      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

usually  the  case,  both  sashes  slide  and  are  balanced  by  weights, 
the  window  is  known  as  a  double-hung  sash  and  frame  window. 
If  one  sash  only  slides,  and  the  other  is  fixed  in  the  frame,  the 
window  is  Bingle-hung.  Figs.  770  to  772  show  the  details  of  a 
sash  and  frame  window  fixed  in  a  one-and-a-half -brick-thick 
wall  and  having  a  stone  head  and  sill. 

For  the  sake  of  appearance,  or  when  it  is  required  to  have 
wider  windows  than  can  be  arranged  with  one  pair  of  sashes, 
two  or  three  pairs  of  sashes  are  often  constructed  side  by  side 
in  the  same  frame.  When  three  pairs  of  sashes  are  used,  it  is 
usual  to  have  the  middle  pair  wider  than  the  others  ;  such  a 
combination  (Fig.  773)  is  named  a  Venetian  window.  The  vertical 
divisions  between  adjacent  pairs  of  sashes  are  called  mullions. 
These  mullions  may  be  constructed  in  several  different  ways. 
If  the  middle  pair  of  sashes  only  is  required  to  slide,  the 
mullions  may  be  solid,  from  1  J"  to  2"  thick,  and  the  sash-cord 
conducted  by  means  of  additional  pulleys  to  the  boxes,  which 
are  at  the  outer  edges  of  the  frame.  Figs.  775  and  777  show  this 
arrangement.  If  it  is  desirable  to  have  all  the  sashes  to  slide, 
the  mullions  must  be  hollow  to  provide  room  for  the  weights. 
Figs.  776  and  778  show  details  of  a  mullion  with  provision  made 
for  one  weight  to  balance  the  two  sashes  adjacent  to  it.  With 
this  arrangement  the  sash-cord  passes  round  a  pulley  fixed  into 
the  upper  end  of  the  weight.  If  stone  mullions  are  used  in  the 
window  opening,  separate  boxings  may  be  made  so  that  each 
pair  of  sashes  is  hung  independently  as  shown  in  Fig.  774, 
and  the  window  becomes,  as  it  were,  two  or  three — as  the  case 
may  be — separate  window  frames,  with  the  sill  and  head  each 
in  one  length  for  the  sake  of  strength. 

Hospital  Lights. — A  type  of  window  specially  suitable  for 
hospitals,  and  also  much  used  in  schools  and  other  buildings,  is 
shown  in  Fig.  779.  It  consists  of  a  sash  and  frame  window  in 
the  lower  part,  with,  in  the  upper,  a  hinged  sash  hung  on  the 
bottom  rail  to  open  inwards.  By  opening  this  upper  sash, 
ventilation  without  draught  is  obtained  at  the  highest  part  of 
the  window. 

The  Hanging  of  Vertical  Sliding  Sashes.— As  shown  in 

numerous  illustrations  already  given,  the  sashes  of  sash  and 

frame  windows  are  balanced  by  cast-iron  or  leaden  weights. 

The   best  hempen    cord   is    employed    for   hanging   sashes  of 

ordinary  size,  while  for  very  \ieavy  s.^ksXYfc-e.  \i\ife  ^•svs&Vi.  Vvafte.  are 


398       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

often  of  steel  ov  copper.  The  staff  bead  and  parting  lath  having 
been  removed,  the  cords  are  passed  over  the  axle  pulleys  (which 
are  best  of  brass  to  prevent  corrosion)  and  are  tied  to  the  upper 
ends  of  the  weights.  The  weights  are  passed  through  the 
pocket  holes  and  suspended  in  the  boxes.     The  pocket  pieces 


Transom 


Elevah'on 

Pio.  779. 


\Z:7^ri : 

Verh'cal  SecHon 

Fig.  780. 

Horizonfal   SecHon. 

Fin.  781. 

Elevation  and  Sections  of  a  Window  with  Vertical  Sliding  Sashes  in 
the  lower  part,  and  Hinged  Sash  above. 

having  been  replaced,  the  upper  sash,  which  slides  in  the  outer 
groove,  is  hung  first,  the  free  ends  of  the  cords  being  either 
nailed  into  grooves  in  the  outer  edges  of  the  sash  (Fig.  783)  or 
secured  by  knotting  the  ends  after  passing  them  through  holes 
bored  into  the  styles  of  the  sash  (Fig.  782).  The  upper  sash 
having  been  hung,  the  parting  laths  are  fixed  into  the  grooves 
in  the  pulley  styles,  and  the  lower  (inner)  sash  is  hung  in  a 
ainiilar  manner,  after  wMch  th^  ata^^  b^a.da  are  screwed  in 


BAY  WINDOWS.  399 

tion.  Care  should  be  bakoa  to  have  the  cords  of  the  right 
fths  :  if  the  cords  for  the  upper  sash  are  too  long  the  weights 

touch  the  bottom  of  the  frame,  and  ceaee  to  balance  the 
ifht  of  the  saah  before  the  latter  is  closed.     If  the  cords  for 

lower  8a«h  are  too  short,  the  weights  will  come  in  contact 
a  the  axle  pulleys,  aud  thus  prevent  it  from  closing.  Several 
jrent  devices  for  hanging  easbes— the  objecta  of  which  are 
er  to  render  unnecessary  the  use  of  weights  or  to  facilitate 
cleaning  of  the  outside  of  the  window— have  been  patented. 


:  Double 
Tenons. 


Fio.  ret. 

^  aash  Cords  tu  Vertii^ally  SlldiDg  Buhes. 

are  in  more  or  less  general  use.     A  detailed  description  of 
re  is,  howevei',  beyond  the  scope  of  this  booit. 
■ay  Windows. — A  bay  window  is  one  that  projects  beyond 

face  of  the  wall.  Tlie  side  lights  may  be  either  splayed  or 
right  angles  to  the  front.  The  window  openings  may  be 
lied  by  having  stone  or  hi'ick  muUions  or  piers  at  the 
lea,  against  which  the  window  frames  are  fixed,  or  the 
■den  framework  ot  the  window  may  be  complete  in  itself, 
en  the  latter  is  the  case,  it  is  usual  to  have  stone  or  brick 
k  to  the  sill  level,  »s  shown  in  Fig,  784.  Bay  windows 
jrally  lend  themselves  to  decorative  ir«a,tmeTA..    "^\fti*OQi& 


WINDOWS. 


401 


Arch  lira  ve . 


lition  of  masonry  or  brickwork  they  often  assume  a  massive 
id  bold  appearance.  When  constructed  of  wood  the  frame- 
rork  is  surmounted  usually  by  a  wooden  cornice,  and  the 
rooden  roof  is  covered  with  lead,  slates  oi*  tiles.    The  window 

Lines  may  be  arranged  as  fixed  lights,  sash  and  frame,  or 
casements.  The  most  usual  arrangement  is  to  have  the  lower 
lights  fixed,  and  the  upper  ones  as  sashes  hinged  to  open  for 
Tentilating  purposes.  Figs.  784  to  786  show  the  details  of 
a  bay  window  with  splayed  side  lights,  the  upper  side  lights 
being  hinged  on  the  transom  to  open  inwards. 

Windows  with  Cnrved  Heads. — When  a  window  opening 
is  surmounted  by  an  arch,  the  top  of  the  window  frame  requires 
to  be  of  the  same  curvature  as  the  under  side  (soffit)  of  the 
arch.   In  the  case  of  fixed 
sashes,  or  of  solid  frames 
with  casement  sashes,  the 
head  of  the  frame  is  '^  cut 
out  of  the  solid."   A  head 
which,  owing  to  the  size 
of    the    curve,     cannot 
easily  be  obtained  in  one 
piece,  is  built  up  of  seg- 
ments, the  joints  being 
radial  to  the  curve,  and 
secured    by     hardwood 

keys.  As  an  alternative  method,  the  head  may  be  built  up 
of  two  thicknesses — with  overlapping  joints — and  secured 
together  by  screws. 

A  sash  and  frame  window  in  such  an  opening  may  have  only 
the  outside  lining  cut  to  the  curve  of  the  arch,  the  inner  side 
of  the  frame  being  left  square.  The  upper  sash  will  then  require 
a  top  rail  with  a  straight  upper  edge  and  a  curved  lower  edge, 
as  shown  in  Fig.  787. 

When  the  head  of  the  frame  has  to  be  curved,  it  may 

(1)  be  built  up  of  two  thicknesses  with  overlapping  joints, 
and  secured  by  screws  ;  it  may 

(2)  be  formed  of  three  thicknesses  of  thin  material,  bent 
upon  a  block  of  the  correct  radius,  and  well  glued  and  screwed 
together ;  or 

(3)  the  head  may  be  of  the  same  thickness  as  the  puUev 
styles,  with  trenches  cut  out  of  the  back  (upper)  side,  1 


Fio.  787.— Elevation  of  upper  part  of  a  Window 
having  Curved  Head. 


402       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

only  a  veneer  on  the  face-side  under  the  trenches.  Wooden 
keys  are  glued  and  driven  into  the  trenches  after  the  head  has 
been  bent  upon  a  block  to  the  required  shape. 

A  strip  of  stout  canvas  glued  over  the  upper  side  will 
strengthen  the  whole  materially.  The  outside  and  inside 
linings  are  in  such  a  case  cut  to  the  required  curvature,  and 
when  nailed  in  position  hold  the  head  in  shape.  The  end 
joints  of  the  linings  may  have  hardwood  cross-tongues. 

Shop  Windows. — The  main  object  in  view  in.  the  construc- 
tion of  shop  windows  is  to  admit  the  maximum  of  light, 
and  to  give  opportunity  for  an  effective  display  of  the  goods. 
The  glass  is  in  large  sheets,  and  therefore  is  specially  thick  to 
secure  the  necessary  strength.  Shop  windows  are  usually 
arranged  as  fast  sheets,  with  provision  for  ventilation  at  the 
top.  The  glass  is  held  in  position  by  wooden  fillets,  and  is  fixed 
from  the  inner  side.  The  chief  constructional  variations  are 
found  in  the  pilasters,  cornice,  provision  for  sign-board,  sun- 
blind,  and  the  arrangement  of  the  side  windows.  Figs.  788  to 
790  show  the  details  of  a  typical  example. 

The  Fixing  of  Window  Frames.— Window  frames  may 
be  built  into  the  wall — which  has  usually  a  recessed  opening 
to  receive  them — as  the  brickwork  proceeds,  or  they  may  be 
fixed  later.  In  the  former  case,  the  ends  of  the  sill  and  head 
project  and  form  horns,  which  are  built  into  the  brickwork  and 
help  to  secure  the  frame.  Wooden  bricks  or  slips  may  also  be 
built  into  the  wall,  the  frames  being  nailed  to  them. 

In  the  latter  case,  the  frames  are  secured  by  wooden  wedges, 
which  are  driven  tightly  between  the  frame  and  the  wall. 
These  wedges  should  be  inserted  only  at  the  ends  of  the  head 
and  sill  and  directly  above  the  jambs  ;  otherwise  the  frame 
might  be  so  strained  as  to  interfere  with  the  sliding  of  the 
sashes.  Window  frames  as  well  as  door  fi'ames  should  be 
bedded  against  a  layer  of  hair- mortar  placed  in  the  recess. 

Linings. — When  window  frames  are  not  of  sufficient  thick- 
ness to  come  flush  with  the  inner  face  of  the  wall,  the  plaster 
may  be  returned  round  the  brickwork  and  finished  against  the 
frame,  or  a  narrow  fillet  of  wood  may  be  scribed  to  the  wall  and 
nailed  to  the  frame  as  shown  in  Fig.  756.  In  dwelling-houses, 
however,  the  more  usual  way  is  to  fix  linings  similar  to  those 
used  for  outer  door  frames  (p.  368).  The  width  of  the  linings 
depends  upon  the  thickness  oi  \^i^  'vviW.  *,  ^V^^  «s\v^\\\d  ^'^xio^ect 


^  ;  Verhcal  Sechoi 

II  


Horizontal   Sech'on. 

Fio.  reo. 


404      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

beyond  the  inner  face  of  the  w&ll  for  a  distance  equal  to  tk 
thickness  of  the  plaster,  and  are  usually  splayed  so  that  thej 
will  not  interfere  with  the  admission  of  light.    The  inaide  of 


window  and  d' 

the  axtMtnvt,  „. __„,  . 

the  linings  and  to  rongb  wood* 


upcuiu^H  usunlly  are  finished  similarly  ;  thus 
baud  motilding,  which  is  secured  to  the  edge  o 


WINDOWS. 


40S 


sides  and  top  in  both  cases.  The  bottom  of  the  window  opening 
is  SnisheJ  with  a  irlndow  board  which  is  tongued  into  the  sill 
of  the  frame.  The  board  is  about  Ij^  inches  thick,  and  is 
made  wide  enough  to  project  beyond  the  auiface  of  the  plaster 
for  a  distance  of  about  16  inches.  The  projecting  edge  is  nosed 
(rounded)  or  moulded  It  is  longer  than  the  opening,  to  allow 
the  lower  ends  of  the  architrave  to  rest  upon  it. 

W'hen  the  walls  are  thiik  the  linings  are  often  framed  and 
panelled.  Such  linings  maj  terminate  on  a  window  board  at 
the  sill  level,  or  the  inner  side  of  the  wall  may  be  recessed 


dow,  Bhc 


Saeb  uid  Fnms 


below  the  sill  level  and  the  linings  carried  to  the  floor  as  showa 
in  Fig.  791. 

Window  Siutters.— Although  not  used  to  the  same  extent 
as  formerly,  wooden  window  shutters  are  fitted  occasionally  to 
close  up  the  window  opening.  Window  shutters,  which  are 
arranged  generally  on  the  inner  side  of  the  window,  may  be 
hinged  as  bon  shutters,  or  may  be  vertically  sliding  shutters. 

Box  slmtteTa  consist  of  a  number  of  leaves  or  narrow  frames 
which  are  rebated  and  hinged  together,  an  equal  number  being 
on  each  side  of  the  window  opening,  the  outer  ones  on  each 
side  being  hung  to  the  window  frame.  When  closed  they 
together  fill  the  width  of  the  window-space,  and  when  open 
they  fold  behind  each  other  so  that  the  ft<mt  oqq  Eottoa  t.'iift 


406      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

jarab  lining  of  the  window  frame.  If  the  walls  are  thick,  the 
ahutters  can  be  arranged  to  fold  in  the  thickness  of  the  wall; 
if  the  wall  is  a  tbin  one  it  is  necessary  to  construct  projecting 
boxes  into  which  the  shutters  fold.  The  nature  of  the  framtDg 
of  the  shutters  depends  upon  the  surrounding  work  ;  it  ia  uiual 
to  have  the  outer  surface  framed  and  moulded,  and  the  inside 
finished  bead-flush.  The  arrangement  of  box  shutters  requires 
that  the  shutters  on  the  same  side  shall  vary  in  width  so  tbat 
they  will  fold  into  the  boxes  on  each  aide  of  the  windov,  the 
outermost  shutter  (which  is  the  widest)  then  acting  as  the  win- 
d<)w  lining.  Fig.  792  shows  a  horizontal  section  through  one  side 
of  a  window,  showing  hinged  shutters  folding  so  that  a  splayed 


Iming  13  obtained  Fig  "93  shows  hinged  shutters  consisting 
of  one  nairow  and  oni,  «ule  shutter  on  each  side  of  the  opening. 
This  arrangement  is  suitable  for  a  thin  wall,  where  it  is 
undesirable  to  have  boxes  for  the  shutters  projecting  bejond 
the  face  of  the  uall  For  hanging  window  shutters  it  in  usual 
to  use  back  flap  hinges  (Fig  717)  the  joint  at  the  corner  of 
the  shuttera  in  Fig  79J  w  nrf,nied  a  rule  joint. 

Sliding  shuttera,  working  in  vertical  groove)^  and  balanced  hy 
weights,  are  sometimes  used.  Tlioy  require  that  the  wall  under 
the  window  sill  shall  be  recessed  ;  the  floor  also  often  needs 
trimming  to  allow  space  for  them  to  slide  sufficiently  low. 
To  hide  the  grooves  in  which  the  shuttei-s  slide,  thin  vertical 
flaps  are  hung  to  the  window  frame,  and  the  window  board 
IB  also  Jiinged  at  the  front  ed^&  bo  allow  the  shutters  to  slide 


Window  Fittings  and 
Fasteners  -  I  n  casement 
and  hinged  saahea  initt  Itlngea 
are  used  These  should  be 
atninf,  eiinnj,li  f  i  the  pur 
pose  piefciulilv  of  brass 
and  tbet  should  whenever 
possible,  have  one  wing  of  ' 
the  hinge  let  into  the  frame 
and  the  other  6ne  into  the 
sash  There  are  ninnj  tjpea 
of  metal  water  tnr  suitable 
for  usL  foi  the  jnmt  between 
the  biittom  rail  and  sill  of 
casement  winduwit  aud  thebe 
matennllj  asaiwt  in  making 
thejoiiilwatuipiouf  Hinged 
casement  sashes  may,  when 
closed,  be  fastened  by  tower 
bolts  (>ig  731)  mub  Delta 
(Fig  732)  or  casement  Rib- 
teneM     (Fig    ll'i^       M.a.wj 


408      A  MANUAL  OF  OARPENTBY  AND  JOINERY. 

special  caaoment-faateners  avo  obtainable,  amoDg  which  one 
of  the  most  serviceable  is  an  BapagnoUtte  bolt.  It  consista 
of  two  long  bars  or  bolta,  which  are  bo  arranged  that  b; 
turning   a   handle   to   which   the;   are   connected,   both   bolta 


AxltPulkjj. 


QwdranTS?  ^^ 

Fanlight  St^ay]  |  Sprir^  Suh  bsttnir. 


are  shot  forward  at  the  same  time,  and  fasten  the  window 
etfectivelj'  at  both  top  and  bottom.  Casement  sashes  are  held 
in  any  required  position  when  open,  by  using  a  casement  »tnt 
(Fig.  796),  one  part  of  which  is  Rcrewed  to  the  sash  and  the 
other  part  to  the  frame.      Iron  qiULilntiits  are  used  generally 


WINDOWS.  409 

for  regulating  the  opening   of  fanlights,   i.e.   sashes   that   are 

hung   as   shown   in    Figs.  752  and  754.      Fig.  797  shows  the 

pivots  or  sash  centres  used  for  pivoted  sashes.      The  opening 

and   closing  of  such  sashes  is  effected  eithei*  by  a  quadrant, 

or  by  means   of  cord^  passing  over  pulleys.     Vertical   sliding 

sashes    are    secured    by    a    Bash    fastener    screwed    on    the 

meeting   i^ils.      Figs.  802  and  803  show   two  kinds    of  sash 

fastener.     The  lower  sash  of  such  a  window  should  always  be 

provided  with  sasli  lifts  (Fig.  804)  for  raising  and  lowering. 


StUDinary. 

Windows  may  be  either  fixed  or  made  to  open.  Those  which 
open  consist  of  a  firame  and  movable  Bashes,  which  are  rebated  to 
liold  the  glass. 

In  casement  windows  the  sashes  open  like  doors.  They  may 
open  inwards  or  outwards.     The  frame  is  solid  and  rebated. 

In  sash  and  ftame  windows  the  sashes  slide  vertically  alongside 
each  other,  and  are  balanced  by  weights.  The  upper  sash  always 
slides  in  the  outer  groove.  The  frame  consists  of  several  parts 
which  together  form  on  each  side  a  box  or  case  in  which  the  weights 
are  suspended. 

Sashes  hing^ed  on  the  bottom  rail  to  open  inwards,  and  sashes 
swinging;  on  pivots,  are  sometimes  used,  especially  in  positions  not 
easily  accessible. 

Sashes  are  framed  together  with  mortise  and  tenon  joints. 

Linings  and  architraves  are  required  with  thick  walls,  to  obtain 
a  finished  internal  appearance. 

Bay  windows  project  beyond  the  face  of  the  wall ;  they  may 
be  arranged  as  fast  sheets,  as  casements  to  open,  or  with  vertical 
sliding  sashes. 

Window  shutters  may  either  consist  of  a  number  of  leaves  hinged 
together  and  folding  into  boxes  at  each  side  of  the  window  (box 
shutters),  or  two  shutters  may  slide  vertically  past  each  other  and 
be  balanced  by  weights. 


Qnestions  on  Chapter  XIV. 

1.  Draw  full-size  section  tlirough  the  sill  of  a  casement  window 
■Opening  inwards.     (C.  and  O.  Ord.,  1896.) 

2.  Draw  sections   through  the  sill,  head,  and    the  styles  of  a 
.casement  window  to  open  outwards.     Scale  J  full  size. 


410       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

3.  Make  one  half  horizontal  and  a  vertical   section  through  a 
r  window  frame  7  ft.  4  in.  high  and  4  ft.  3   in.  wide,  fitted  with 

*^    a  pair  of  French  casements  to  open  inwards.     Scale  2  in.  to  the 
foot ;  give  details  to  a  larger  scale.     (C.  and  G.  Ord.,  1902.) 

4.  Draw  to  a  scale  of  one  inch  to  a  foot,  plan  and  section  of  an 
ordinary  French  casement  window  to  open  inwards.     Show  the 

\/^  linings  for  a  14  in.  wall,  and  give  full-size  sections  of  devices  for 
excluding  the  weather.     (C.  and  G.  Ord.,  1895.) 

5.  Draw  plan  and  section  to  scale  1 J  in.  to  a  foot  of  a  three-light 
y     casement  with  solid  frame  and  mullions.    Size  of  opening  5  ft.  6  in. 

by  3  ft.     Give  section  through  sill  J  full  size.     (C.  and  G.  Ord., 
1897.) 

6.  Make  vertical  and  horizontal  sections  of  a  solid  window  frame 
with  a  2  in.  sash  hung  on  pivots,  and  show  how  the  beads  are  cot. 
The  size  of  the  window  opening  is  4  ft.  high  and  2  ft.  9  in.  wide. 
Scale  2  in.  to  the  foot.     (C.  and  G.  Ord.,  1902.) 

7.  Draw  a  section,  one-quarter  full  size,  through  the  oak  sill  and 
lower  portion  of  a  2  in.  double  hung  sash,  showing  the  method  you 
w(juld  adopt  to  prevent  the  admission  of  water ;  also  similar  sections 
through  a  transom  with  opening  fanlight,  and  the  lower  portion  of 
a  French  casement  to  open  inwards  in  an  exposed  position.  (C.  and 
G.  Ord.,  1894.) 

8.  Draw  out,  full  size,  a  horizontal  section  through  one  of  the 
jambs  of  a  window  in  a  brick  reveal,  having  the  usual  cased  frame 
and  2  in.  deal  ovolo  sashes.  Draw  also  a  vertical  section  through 
the  same  sashes  at  the  meeting  rail.     (C.  and  (».  Prel.,  1900.) 

9.  Draw  half  horizontal  and  vertical  sections  (scale  2  in.  to  1  ft.) 
of  2  in.  double-hung  sashes  with  cased  frame,  opening  3  ft.  by  5  ft., 
adapted  to  exposed  positions.     (C.  and  G.  Ord.,  1899.) 

10.  Draw   \    full-size    sections    through    head,    sill,   jamb,   and 
/     meeting  rails  of  an  ordinary  double-hung  sash  window  in  a  14  inch 

wall.     (C.  and  G.  Ord.,  1896.) 

11.  Make  half  elevation,  plan,  and  vertical  section  of  a  pair  of 
2  in.  double-hung  sashes  and  cased  frame  with  semicircular  head ; 
width  of  opening  4  ft.  ;  height  to  "springing  line"  5  ft.  Give 
details  to  show  the  best  method  of  constructing  the  head  of  the 
frame.     Scale  li  in.  to  1  foot.     (C.  and  G.  Ord.,  1903.) 

12.  Make  rather  more  than  half  elevation,  vertical  and  horizontal 
sections  of  a  boxed  Venetian  window-frame,  6  ft.  6  in.  wide  and 
5  ft.  high.     (C.  and  G.  Hon.,  1904.) 

13.  Draw  plan,  elevation  and  section  of  a  double-boxed  Venetian 
^  windiow  of  three  lights,  to  occupy  au  oi^wiu^  m  a  wall  two  bricks 


\^ 


QUESTIONS  ON  CHAPTER  XIV.  411 

thick  ;  opening  to  he  10  ft.  wide  hy  7  ft.  6  in.  high  in  the  clear. 
Scale  for  the  general  drawings,  ^  in.  to  a  foot ;  details  not  less  than 
i  full  size.     (C.  and  G.  Hon.,  1903.) 

14.  Draw  plan  and  section  to  scale  of  ^  in.  to  a  foot  of  a  shop 
front,  showing  arrangement  for  giving  light  to  ha^ement.  Frontage 
18  ft.  ;  height  from  floor  to  ceiling,  13  ft.     (C.  and  G.  Hon.,  1897.) 

15.  Draw,  in  plan,  elevation  and  section,  an  ordinary  shop  front, 
to  occupy  16  ft.  There  is  to  be  a  light  to  the  basement  under  the 
shop-board.  Scale  )  inch  to  a  foot ;  with  details  to  1  inch  to  a 
foot. 

16.  An  ordinary  sash  window  set  in  an  opening  6  ft.  wide  by  8  ft. 
6  in.  high  in  the  brickwork,  in  a  brick  and  a  half  wall,  is  to  have 
folding  shutters.  Draw  the  plan  of  the  shutter  boxing  and 
architrave,  taking  in  half  the  window,  to  a  scale  of  not  less  than 
1  in.  to  1  ft.,  or  larger  than  1)  in.  to  1  ft.  Show  the  grounds  or 
other  fixing.     (C.  and  G.  Hon. ,  1900. ) 

17.  A  window  has  a  6  ft.  opening.  It  is  to  be  fitted  with  splayed 
folding  boxing  shutters.  The  sofl&t  is  framed.  Write  a  brief 
description  of  the  method  of  fixing  the  various  parts.  (C.  and  G. 
Hon.,  1898.) 

18.  Draw,  to  a  scale  of  2  ins.  to  one  foot,  a  horizontal  section 
through  one  side  of  a  double  hung  sash  and  frame  window  in  a    J 
14  in.  brick  wall  showing  hinged  shutters  arranged  to  open  back 
against  the  inside  face  of  the  wall.     Width  of  opening  3  ft.  6  in. 

19.  Describe  back  flap,  rule  joint,  and  give  illustrations  of  their 
use.     (C.  and  G.  Ord.,  1898.) 

20.  Give  a  plan  and  section,  |  inch  to  the  foot  scale,  of  lifting 
shutters  to  a  properly  cased  sash  frame  3  feet  6  inches  wide,  fixed 
4 J  inches  in  reveal  (wall  1  foot  10^  inches  thick)  and  show  the 
splayed,  moulded,  and  panelled  linings,  window  backs,  architraves, 
etc.,  complete.     (C.  and  G.  Hon.,  1892.) 


CHAPTEE   XV. 

BOOF-LIQHTS  AND  CONSEBVATOBIES. 

In  many  buildings  it  is  necessary  to  have  the  top  rooms  lighted 
by  windows  in  the  plane  of  the  roof  or  slightly  elevated  above 
the  roof  surface.  Such  windows  are  called  roof-lights  or  sky- 
lights. They  may  either  be  "  fixed "  into  the  roof,  or  be  con- 
structed to  allow  of  being  opened  for  purposes  of  ventilation. 
The  chief  difierence  between  the  frames  of  roof-lights  and 
the  sashes  described  in  Chap.  XIV.  is  that  in  the  former,  cross 
bars  are  not  used,  and  the  bottom  rail  is  thinner  by  the  depth 
of  the  rebate  than  the  other  parts  of  the  sash.  These  modi- 
fications are  necessary,  as  will  be  seen  from  the  illustrations, 
to  allow  the  free  escape  of  rainwater. 

Owing  to  their  exposed  positions,  it  is  specially  necessary 
that  the  timber  used  for  all  roof -lights  shall  be  of  the 
best  quality,  well  seasoned,  and  entirely  free  from  sapwood, 
shakes,  loose  knots,  and  other  defects.  Red  deal  is  in  general 
the  best  wood  for  this  purpose.  Further,  all  the  joints  should 
be  well  painted  with  lead  paint  before  the  framework  is  put 
together,  and  the  framework  itself  requires  re-painting 
periodically. 

There  are  many  dififerent  methods  of  arrangement,  some  of 
which  are  described  below. 

Fixed  Skylights. — The  simplest  roof-light,  and  one  that 
is  specially  applicable  to  large  sheds  of  the  warehouse  type, 
is  constructed  by  placing,  on  each  common  rafter,  a  double 
rebated  bar,  from  3  to  5  feet  long,  as  shown  in  Fig.  805.  In 
the  rebates  of  these  bars  the  squares  of  glass  are  fixed.  At 
its  upper  end  the  glass  fits  into  a  grooved  cross  rail,  and  the 
slates  or  Jead  flashings  overViaiig  Wiia.    X.\.  ^\i^  lo^^r  eud^  the 


ROOF-LIGHTS  AND  CONSERVATORIES. 


413 


glass  is  so  arranged  that  it  overlaps  the  slates,  or  sheet  lead 
may  be  used  to  make  a  watertight  joint. 

An  alternative  method  is  to  "trim"  the  common  rafters, 
so  that  a  rectangular  space,  equal  in  size  to  the  required 
skylight,  is  obtained.  The  frame  of  the  light  consists  of 
two  styles,  a  top  rail  of  the  same  thicl^ness  as  the  styles, 
and  a  Irattom  rail  the  thickness  of  which  is  less  than  the 
thickness  of  the  other  parts  by  the  depth  of  the  rebate. 
Intermediate  bars  parallel  to  the  styles,  and  in  the  same 
direction  as  the  slope  of  the  roof,  are  placed  at  from  12  to  16 


Slates 


Seaion  through  A. B 


Fio.  806. 


Slates 


Fig.  805. — Vertical  Section  through  part  of  a 
Roof,  showing  a  fixed  Skylight. 


inches  apart,  as  it  is  not  advisable  to  have  the  sheets  of  glass 
more  than  that  width.  As  these  lights  are  in  the  slope  of 
the  roof,  there  are  no  cross  bars,  therefore  the  sheets  of  glass 
should  be  as  long  as  possible.  As  the  glass  used  for  glazing 
such  lights  is  thicker  than  in  ordinary  windows,  it  is  necessary 
to  have  the  bars  thicker  than  in  ordinary  sashes,  and  a  rebate 
at  least  one  inch  deep  is  required.  The  thickness  of  the  frame 
depends  upon  its  size,  but  should  never  be  less  than  2j  inches. 

Glass  may  be  fixed  in  wooden  frames  either  by  means  of 
small  brads  and  putty,  or  by  wooden  fillets.  When  putty 
is  used,  it  is  essential  that  the  rebates,  which  are  to  hold  the 
glass,  be  previously  painted  or  "primed."  The  paint  pre- 
ventB  the  wood  from  absorbing  the  o\\  oi  t\ift  ^wXXi^.    '^"'^fesssav 


414       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

provision  is  also  needed  for  the  removal  of  condensed  water,  which 
is  invariably  found  where  skylights  are  used.  The  condensa- 
tion is  most  marked  in  rooms,  such  as  mills,  in  which  the  air  is 
hot  and  moist.  To  provide  channels  for  the  condensed  water, 
grooves  are  cut  along  the  sides  of  the  bars  (Fig.  809)  and 
styles.  Sinkings  are  also  made  upon  the  upper  side  of  the 
bottom  rail,  as  shown  in  Fig.  815,  to  prevent  the  water  from 
being  drawn  by  capillary  attraction  between  the  glass  and  the 
rail. 

The  Joints  between  the  sides  of  the  light  and  the  roofing 
material — slates  or  tiles — are  made  watertight  by  sheet  lead 
flashings  which  overlap  the  woodwork  of  the  frame.     Fig.  807 


Slates   s 


S\aUs 


Fig.  807. — Vertical  Section  through  part  of  a 
Roof  showiug  a  fixed  Framed  Skylight. 


is  a  section  showing  a  framed  roof-light  resting  on  the  common 
rafters.  The  bottom  rail  overlaps  the  slates  or  tiles,  and  this 
joint  is  also  made  watertight  with  sheet  lead  as  shown  in 
section  in  the  illustration. 

Fig.  808  shows  in  section  an  elevated  skylight  fixed  upon  a 
"  curb  "  near  the  ridge  of  a  roof.  Fig.  810  is  a  section  through 
a  fixed  skylight  in  a  shed-roof. 

Hinged  Skylights.— Skylights  which  are  hinged  to  open 
are  fitted  upon  the  upper  edge  of  a  curb  or  frame  fixed  in  the 
plane  of  the  roof,  the  common  rafters  being  "trimmed"  to 
the  required  size  to  receive  the  curb.  The  curb  is  made  from 
material  1|^  to  2  inches  thick,  and  of  width  such  that  its  upper 
edge  stands  from  4  to  6  inches  above  the  plane  of  the  roof. 
The  an^le  Joints  of  the  curb  may  be  dovetailed  or  tongued 
and  nailed.    The  sajdi  frame  Test?^  w^on  Wv^  w^^^x  ^^^^  ^1  vJckfc 


ROOF-LIGHTS  AND  CONSERVATORIES. 


415 


curb  ;  it  is  from  2  to  2^  inches  thick,  and  consists  of  styles 
and   top  rail  of  the  same  thickness,  and  a  bottom  rail  which 


Sheet  Lead 


Fia.  809. 


Collar  Beam 


Fio.  808.— Section  through  an  Elevated  Skylight 
fixed  at  the  Ridge. 

(because  the  glass  overlaps  it)  is  thinner  than  the  styles  by 
the  depth  of  the  rebate.     Bars  are  inserted  in  the  direction 


Ridge  Tile 


Slates 


Fig.  810. — Section  through  part  of  a  Shed-roof,  showing  a  fixed  Skylight. 


of  the  slope  of  the  roof,  and  the  butt  hinges  used  for  han^in^ 
the  sash  are  invariably  fixed  on  the  underaida  oi  \\i^  \*o^  "c^^. 


416       A  xMANUAL  OF  CARPENTRY  AND  JOINERY. 

Considerable  care  is  requii'ed  to  make  the  Joint  betweeo  the 
gash  and  the  curb  watertight.  Fig.  814  shows  the  upper  edge 
of  the  curb  rebat«d  to  form  a  tongue  which  fits  into  a  corre- 
sponding groove  cut  in  the  underside  of  the  sash.  Another 
way  is  to  have  the  edge  of  the  curb  square,  and  to  fix  a  toogati 
fillet  around  the  underside  of  the  saah  so  that  it  overlaps  the 
curb  as  shown  in  Fig.  813.     This  type  of  skylight  is  extensively 


used  for  lighting  attics  and  staircases  of  dwelling-houses.  Figs. 
812  to  814  show  sections  of  such  a  skylight  with  the  main 
dimensions  indicated  thereon. 

The  joints  hetween  the  curb  and  the  I'oofing  slates  or  tiles 
are  made  weatherproof  with  sheet  leaA.  At  the  upper  end— 
the  back  of  the  curb — a  small  lead  gutter  is  foi'ined,  with  the 
lead  going  underneath  the  slat«s  and  overlapping  the  upper 
edge  of  the  curb.  The  sides  of  the  curb  may  lie  flashed  with 
soakers — short  lengths  of  sheet  lead  which  are  worked  in 
between  the  slates — or  the  joint  may  be  made  with  one  strip  of 
lead  formiug  a  small  gutter  down  the  side  of  the  curb.  In 
either  case  the  lead  overlapa  the  ap'pet  fci^a  o^  ftie  t-it\i.     t.\. 


ROOF-LIGHTS  AND  CONSERVATORIES.  417 


.  4 

* — 

r-l 

t!^3 

s 

-If- : 

/ 


418       A  MANUAL  OF  CARPENTRY  AND  JOINER^. 

\^ 
the  lower  end  of  the  curb,  the  lead  overlaps  the  slates-    To 

prevent  water  from  rising  between  the  glass  and  the  upper  side 

of  the  bottom  rail,  sinkings  are  cut  into  the  rail  as  shown  in 

Fig.  815. 

Dormer  Windows. — Instead  of  having  the  light  in  or 
parallel  to  the  plane  of  the  roof,  it  affords  a  more  artistic 
treatment  of  the  roof,  and  often  gives  a  better  result  in  light- 
ing, if  the  window  is  fixed  vertically.  The  general  arrangement 
of  the  framing,  as  well  as  of  the  sashes,  depends  upon  the 
kind  of  roof,  the  width  of  the  window  required,  and  the  general 
style  of  architecture  of  the  building. 

The  construction  of  a  dormer  window  necessitates  trimming 
of  the  rafters,  and  the  arrangement  of  projecting  framework, 
the  front  of  which  consists  of  comer  posts  and  crossrails— 
rebated  to  receive  hinged  sashes — which  are  connected  to  the 
main  roof  by  other  crossrails  and  by  braces.  This  framework 
is  surmounted  by  a  roof  which  may  be  either  ridged,  of  curved 
outline,  or  flat.  By  arranging  a  ridged  roof  to  overhang,  and 
adding  suitable  barge  boards  and  finial  (Fig.  819),  a  dormer 
window  may  be  made  to  improve  the  general  appearance  of  the 
roof  of  a  building.  The  sides  of  the  dormer  may  be  either 
boarded  and  covered  witli  the  same  kind  of  material  as  the  roof, 
or  they  may  be  framed  for  sidelights. 

As  dormer  windows  are  generally  in  exposed  positions,  and 
the  sashes  are  arranged  as  casements  to  open,  their  efficiency 
depends  largely  upon  the  perfection  of  the  joints  between  the 
sashes  and  the  frame.  The  methods  of  arranging  tliese  joints 
are  explained  in  detail  in  Chap.  XIV.  to  which  reference  should 
be  made.  It  ought  to  be  mentioned,  however,  that  with  sashes 
hung  folding,  semicircular  tongues  on  their  hanging  styles 
(Fig.  745)  are  by  far  the  best.  Figs  817  and  818  give  the 
details  of  a  dormer  window,  with  sidelights,  fixed  in  a  roof  of 
ordinary  pitch.  The  sashes,  which  are  hung  folding,  open 
inwards.  The  roof  may  be  boarded  and  covered  with  lead,  or 
it  may  be  covered  with  slates  or  tiles.  The  joints  between  the 
roofing  slates  of  the  main  roof,  and  the  loof  and  sides  of  the 
dormer,  are  made  weather-proof  with  sheet-lead  flashings. 
Figs.  819  and  820  show  a  dormer  window  fixed  in  a  Mansard 
roof  ;  in  this  example  there  are  no  side  lights.  Figs.  821  and 
822  show  a  three-light  dormer,  of  which  the  middle  sash 
only  is  hiuged  to  opeti.    TV\ft  Tool  \3i  \Xi\'&  <»."6>^  \s,  ^^.-jy.^,^  -M^d  is 


ROOF-LIGHTS  AND  CONSERVATORIES.  419 


fliwithrwisliLtiC^— ill       wW  I  Vertical  Section 
^^-     •*      I       1     i      f/^   ^)    through  A  B 


DaColls  of  a  Daimer  Wlndon  in  t,  Slated  Roof  of  ordloHry  Fl 


Dormer  Window  In  a  Mttnawd  tl 


420       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

covered  with  lead ;  it  ha«  a  wooden  cornice  around  the  upper 
edges. 

Large  Skylights  and  Lantern  Lights.— For  lighting  tJie 
well  of  a,  large  utaircaBe,  or  a  room  which,  for  Boue  reason, 
cannot  be  lighted  with  side  windows,  Bpecially  large  skylighU 
are  often  necessary.  Tliese  are  of  more  elaborate  construction 
than  the  skylights  already  described ;  they  vary  conaiderablj 
in  size,  shape,  and  design  ;  the  plan  may  be  I'ectangular, 
polygonal,  circular,  or  elliptical,  and  the  outline  may  bs 
pyramidal,  conical,  or  spherical.    The  framework  may  be  ot 


TT 

i 

'// 

^ 

1 

4= 

Front  'Eleva 

Tbree-lie 

tion 

4 

/  Section  through 

A.B. 
Roof 
Purlin 

Fio.  S22. 

either  wood  or  iron.  To  support  auch  a  skylight,  a  strong 
wooden  curb  is  framed  into  the  roof,  and  projects  from  6  to 
9  inches  above  the  roof  surface.  The  joints  between  the  curb 
and  the  roof  are  made  watertight  with  sheet  lead  The 
framework  of  the  skylight  may  consist  of  rebated  quartering, 
with  sepai'ate  lights  which  fit  into  the  rebates  of  the  framing  ; 
or  the  sashes  themselves  may  be  constructed  with  strong  angle 
styles,  which  are  mitred  together,  and  provided  with  either  a 
hardwood  tongue  inserted  in  the  joint,  or  with  a  wooden  roll 
on  the  top  to  keep  out  water. 

With  skylights  of  this  description,  channels  for  condensed 
irater  should  always  be  provided.  These  are  placed  at  the 
upper  inner  edge  of  the  curVi,  tA\e  remsiini4eT  lA  'Oiv«  vtisiiss  i«ai 


ROOF-LIGHTS  AND  CONSERVATORIES. 


421 


of  the  curb  being  covered  by  either  panelled  framing  or  match 
boarding. 

Figs.  823  and  824  give  details  of  a  skylight  having  the  form 
of  a  square  pyramid.  In  this  example  the  four  triangular 
lights  are  mitred  at  tlie  angles,  and  have  wooden  rolls  over  the 


Skylight  of  Curved  Outllm 


al  akyllght. 


joints.     Figs.  825  and  826  show  elevation   and   part  plan  of  a 
skylight  with  a  curved  roof  surface. 

A  lantern  Ilfclit  differs  from  the  skylights  just  described  in 
having,  in  addition,  vertical  rideltelits.  The  sidelights  consist 
of  gashes,  which,  by  being  hinged  or  pivoted,  are  often  avail- 
able for  ventilation.  As  they  are  in  exposed  positions,  the 
greatest  care  is  inquired  in  order  to  obtain  watertight  joints, 
the  detailed  conatmction  of  which  is  conaideTei  \tiOiw^-'S^  . 


422      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

When  the  Bidelighta  are  hinged  on  the  bottom  rail,  as  in 
Fig.  827,  they  open  inwards  ;  when  on  the  top  rail  (Fig.  S28J, 
they  opec  outwards.  When  they  are  hung  on  pisots,  th« 
pivots  are  fixed  slightly  above  the  middle  of  the  sash,  wliich 
opens  in  the  manner  shown  in  Fig.  829.  Figs.  830  to  633  sliov 
dutails  of  a  rectangular  opening  surmounted  by  a  lantern  light 
which  is  hipped  (p.  216)  at  both  ends,  and  haa  sidelights 
arranged  to  open  inwards. 


The  eonstructiiiii  of  akylighta  and  lantern  lights  affords  good 
examples  of  the  a|>plicatii>n  of  geometry  to  practical  work  a» 
described  in  Chap.  III.  When  the  roof-lights  are  pyramidal  as 
shown  in  Figs.  624  and  831,  and  a  separate  frame  is  constructed 
as  shown  in  Fig.  831,  the  methods  of  obtaining  the  lengths  and 
bevels  of  the  hip  raftera  are  similar  to  those  described  in 
Chap.  TX.,  p.  248.  When  the  roof-lighta  mitte  against  one 
another,  the  sizes  of  the  lights  and  the  bevels  of  the  angle- 
styles  which  mitre  together  are  obtained  as  shown  at  X  in 
Fig.  833.  With  lights  of  curved  outline,  the  shapes  of  the  hip 
rafters  or  angle-styles,  as  well  as  the  developed  surfaces,  are 
obtained  as  explained  on  p.  2^5. 


ROOF-LIGHTS  AND  CONSERVATORIES.  423 


■I  n  Untera  Light  flsod  on  a  Flat  Root. 


424       A   MANUAL  OF  CABPENTBY  AND  JOINEEY. 

Laj.ligllts. — At  the  ceiling  level  of  roof-lighfca  used  tor 
staircase  welln,  or  in  similar  positions,  it  is  often  consideied 
adviEiiable,  for  the  Rake  of  appearance,  to  have  a  hoi'izontal  secood 
light  called  a  lay -light.  This  consists  of  a  sash, — or  if  the  apB(« 
is  large,  a  niiinber  of  saahea — lixed  into  frames  in  the  ceiliog. 
The  chief  feature  of  ]a_v-lights  is  in  the  attempt  at  decoration 
hy  arranging  the  bars  in  some  ornamental  design  (Figs.  834 
and  836).  The  lay-lights  are  often  glazed  with  ornanfcnt&l 
glass,  which,  although  it  improves  the  appearauce,  diminishes 
the  amount  of  light  transmitted. 


GreenbooBes  and  Conservatories.— In  this  type  of  building, 
which  is  largely  constructed  of  wood  and  glaan,  the  framework 
is  usually  of  moulded  and  I'ebated  quartering,  with  side  sashes 
fiied  in  fhe  rebates.  As  in  the  case  of  skylifjlits,  the  roof -lights, 
whicli  in  this  cane  reach  from  the  ridge  to  the  eavea,  have  no 
cross  bai-s,  since  these  would  impede  the  flow  of  water  running 
down  the  sliiiw  of  the  roof.  Cai'o  should  be  taken  to  have 
the  b:irH  strong  enough  to  carry  the  glass  without  sagging  ;  aud 
it  is  well  to  reiiieinbei'  that  when  a  roof  is  of  Hat  pitch  a  heavy 
snowstorm  will  thixiw  a  large  additional  weight  u]icin  it,  while 
with  d  xteep  roof  the  wind  Wi  mudi  \io'«cy,     Tlw  distance 


EOOr-LTGHTS  AND  CONSERVATORIES.  423 

apirt  <if  tlie  bars  which  carry  the  glasa  inuges  from  12  to  18 
iiichea,  and  the  lengths  of  bLe  aheetH  uf  g]asn  shniild  be  as  great 
an  poBBibie,  so  aa  to  diminisli  the  numlier  of  crnsa-joinCs,  sinue 
ihese  allow  of  iiccumulationa  of  dii't  which  cannot  be  removed 
easily.  TheKe  roof-lighta  are  constructed  in  exactly  the  name 
manner  as  skylights  ;  they  ai'e,  however,  often  much  larger,  and 
require  to  be  thicker,  unless  purlins  are  placed  to  eiipport 
Lheni.     When,  as   is   often    the  caae,  jsirfc   of  the  rotif-llght  is 


made  to  open,  this  part — often  a  narTOw  atrip  at  the  highest 
pai't  of  the  roof  (Fig.  838) — is  made  as  a  separate  light,  which 
overlaps  the  upper  eilge  of  the  fixed  lower  light.  Additional 
ventilation  is  Eecui-ed  by  arranging  the  side  sashes  to  open. 

The  above  description  is  intended  merely  to  outline  the  broad 
principles  of  the  construction  of  conservatories,  but  it  ahould 
be  remembered  that  the  details,  while  conforming  to  casement 
aud  roof- light  conatruction  generally,  lend  themselves  to 
considerable  variation  in  design  and  arrangement.  Three 
typical  examples  are  illustrated  in  Figs.  836,  637,  and  838. 
1  of  Klaziii£wliio\x  mTOLjM^Jilw,  ? 


ROOF-LIGHTS  AND  CONSERVATORIES.  427 

and  replacing  of  glass,  are  in  use.  It  is,  however,  beyond  the 
scope  of  this  book  to  deal  with  such. 

Fasteners. — Because  roof -lights  are  fixed  at  the  highest 
parts  of  a  building,  they  are  useful  for  purposes  of  ventilation. 
On  the  other  hand,  their  position  renders  them  difficult  of 
access,  so  that  the  means  of  opening  and  regulating  the  sashes 
requires  special  consideration. 

Pivoted  rods,  pulleys  and  cords,  quadrants,  levers,  etc.,  aie 
among  the  devices  used  for  this  purpose.  The  position  and  the 
method  of  hanging  the  sash,  the  general  style  of  the  building, 
the  cost,  and  other  considerations  will  of  course  decide  which 
particular  type  of  regulator  is  most  suitable. 


Summary. 

Roof-li£rlits  may  be  fixed  or  they  may  be  arranged  to  open.  They 
may  be  in  the  plane  of  the  roof  or  elevated  above  its  surface. 

Lead  flasliixigs  are  required  to  render  watertight  the  joints 
between  roof-lights  and  slates  or  tiles. 

A  dormer  window  is  an  arrangement  of  vertical  lights  on  a 
sloping  roof  surface.  The  construction  of  the  projecting  roofed 
framework  necessitates  trimming  of  the  rafters.  The  lights  often 
open  as  casements. 

Large  elevated  skylights  are  supported  by  strong  wooden  curbs 
framed  into  the  roof.  Lantern  lights  have  in  addition  vertical  side 
lights. 

A  horizontal  light  fixed  at  the  ceiUng-level  directly  below  a  roof 
light  is  called  a  lay  light. 

The  principles  governing  the  construction  of  window  framing  and 
roof-lights  are  applicable  also  to  wooden  framed  greenhouses  and 
conservatories. 


Questions  on  Chapter  XV. 

1.  Draw,  to  a  scale  of  3  in.  to  one  foot,  cross  sections  to  show 
fully  alternative  methods  of  constructing  the  fixed  skylight  shown 
in  the  roof  of  the  building  illustrated  in  Fig.  517. 

2.  The  lighting  of  a  large  shed  is  effected  by  fixing  roof- lights 
arranged  as  shown  in  Fig.  810.  Draw  the  complete  details,  show- 
ing the  construction  of  the  roof-lights,  to  a  scale  of  2  in.  to  one 
foot. 


428       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

3.  A  skylight  is  to  be  placed  in  a  sloping  roof.     Give  sketche^j* 

showing  the  construction  of  the  skylight,  and  how  you  would  trimLfc^j^ 
around  the  opening.  The  void  is  to  be  finished  internally  with!  i^^ 
linings.     (C.  and  G.  Ord. ,  1904. )  ■    I  lU 

4.  Draw  to  scale  ot  l^  inches  to  one  foot,  a  plan  and  two  vertical Lu  ^ 
sections  of  the  hinged  skylight  shown  in  Fig.  811.  Show  all  theLw^ 
details  of  the  carpenters'  and  the  plumbers*  work.  Size  of  opening  |tc^ 
(between  common  rafters)  4  ft.  6  in.  by  3  ft. 

5.  Make  a  drawing  of  a  small  skylight,  to  be  fixed  in  a  flat  roof,  1 
and  give  details  to  show  how  the  weather  is  kept  out.     (C.  and  G 
Ord.,  1898.) 

6.  Draw  all  the  details  of  a  dormer  window  fixed  in  a  slated  roc 
which  is  inclined  at  45"*  to  the  horizontal.     Show  fixed  side-lights, 
and  casement  sashes  hung  folding  to  open  inwards  in  the  front  part. 
Scale  2  in.  to  one  foot. 

7.  Give  a  section  through  a  Mansard  roof  30  feet  span,  showi 
all  details  connected  with  gutter  behind,  the  parapet  in  front,  a 
a  skylight  in  upper  front  slope  of  roof.     (C.  and  G.  Ord.,  1892.) 

8.  Make  plan,  elevation,  and  section  of  a  dormer  window,  8  ^t. 
wide  over  all,  divided  into  three  lights,  one  fixed,  the  others  on 
centres,  the  openings  for  lights  to  be  3  ft.  high.  The  dormer  to  be 
in  the  slope  of  a  roof  at  45°  pitch,  and  to  be  covered  with  a  lead  flat. 
Show  the  method  of  trimming  the  opening  and  the  details  of 
framing,  and  all  precautions  to  be  taken  for  keeping  water  out  and 
getting  rid  of  condensation,  and  describe  the  materials  to  be  used. 
(C.  andG.  Hon.,  1904.) 

9.  Draw  to  scale  J  inch  to  a  foot,  section  through  a  skylight  over 
a  billiard  room,  the  clear  width  being  8  ft.     (C.  and  G.  Hon.,  1896.) 

10.  A  lantern  light,  8  ft.  by  5  ft. ,  is  to  be  fitted  to  a  billiard 
room,  covered  witli  a  lead  flat.  Draw  rather  more  than  quarter  of 
plan  and  half  the  vertical  section  of  the  light.  Any  necessary 
details  may  be  drawn  to  a  larger  scale.  Show  clearly  how  you 
would  keep  it  watertight,  and  provide  for  ventilation.  (C.  and  G. 
Hon.,  1901.) 

11.  It  is  proposed  to  cover  a  space,  12  ft.  by  6  ft.,  in  an  exposed 
situation  with  a  lantern  light.  Give  a  plan  and  longitudinal  section 
of  same  to  a  scale  of  half  an  inch  to  a  foot.  Also  give  details, 
quarter  full  size,  of  sections  of  upper  part  of  light  and  lower  part  of 
sash  and  junction  with  roof.  The  light  is  to  be  made  to  ojjeii. 
(C.  andG.  Hon.,  1894.) 

12.  Draw  to  a  scale  of  J  inch  to  a  foot  the  construction  of  a  flat 
iead-covered    roof    over  a    room  2ft  i\..  \y5  \%   ix..,  ^\vciNN\w<^  n>bj^ 


QUESTIONS  ON  CHAPTER  XV.  429 

3nient  for  a  lantern  light  10  ft.  by  9  ft.,  and  give  details, 
;htli  full  size,  through  rolls,  gutter,  and  one  side  of  skylight. 
IG.  Ord.,  1895.) 

Draw  to  scale  of  ^  in.  to  a  foot  a  lantern  light,  elliptical  on 
ft.  long,  4  ft.  wide,  and  3  ft.  6  in.  high  internal  dimensions, 
low  you  would  get  cuts  or  bevels  of  bars  at  top  and  bottom. 
IG.  Hon.,  1897.) 


j 


CHAPTER  XVI. 
STAIBCASE  WOBK  AND  HANDBAILmO. 


\ 


Definition  of  Terms. — As  a  means  of  obtaining  access  to  the 
upper  rooms  of  a  building  it  is  usual  to  provide  a  space  in 
which  is  arranged  a  series  of  steps.  This  space  is  named  the 
staircase,  and  the  combination  of  steps  is  named  a  flight  of  stairs. 

"Wooden  stairs  consist  of  horizontal  treads,  generally  supported 
by  vertical  risers  placed  under  the  front  edges  of  the  treads ; 
and  string  boards  which  support  the  ends  of  the  treads  and 
lisers.  The  front  edge  of  each  tread  usually  overhangs  the 
riser  under  it,  and  is  nosed  or  moulded.     The  line  of  nosings  is^ 

an  imaginary  line  parallel  to  the  edges  of  the  string  boards  and 

touching  the  nosing  of  each  tread  in  a  flight. 

The  going  of  a  stair  is  the  horizontal  distance  from  the  face  of 
the  lowest  riser  to  the  face  of  the  highest  riser  in  the  same 
flight.     The  width  of  the  tread  is  measured  from  the  face  of  on< 
riser  to  the  face  of  the  next,  any  overhanging  nosing  not  beinj 
taken  into  account.     The  total  rise  is  the  height  from  floor 
floor,  although  the  word  "  rise "  usually  refei's  to  the  heighC:> 
from  the  top  of  one  tread  to  the  top  of  the  next  one  above  it  — 
Parallel  rectangular  treads  in  a  flight  are  nanied  fliers  ;  when  i€> 
is  necessary  to  change  the  direction  of  a  flight  of  stairs,  say" 
through  a  right  angle,  either  winders  (triangular  treads)  or  9* 
square  landing  called  a  quarter-space  landing  must   be  used* 
The  middle  tread  of  three  winders  is  four-sided  (kite  shaped^, 
and  is  named  the  kite  winder.     When  the  width  of  the  staircase 
is  at  least  double  the  width  of  the  stairs,  and  the  stairs  ar^ 
arranged   in    two   flights   running   in   opposite  directions,   th^ 
change  of  direction  (through  two  right  angles)  may  be  obtained 
by   winders   only,  by   winders    and   a   quarter-space    landing 


STAIRCASE  WORK  AND  HANDRAILING. 


431 


(Fig.  841),  or  by  a  landing  extending  the  width  of  the  staircase, 
and  called  a  half-space  landlTig.  It  is  sometimes  necessary  to  have 
treads  which  are  a  little  wider  at  one  end  than  at  the  other,  as 
shown  in  Fig.  880 ;  these  treads  are  named  balancing  or  rtandng 


[^10.  839.— Sketch  of  part  of  a  Flight  of  Stairs,  allowing  Coubtructional 

Details. 

tread&l  The  lowest  tread,  or  sometimes  two  of  the  treads  at  tlie 
hottonl  of  a  flight,  may  be  of  different  shape  from  the  fliers,  to 
allow  elf  additional  room,  or  to  improve  the  appearance  of  the 
Btaoa.  ■  A  step  which  has  a  carved  front  edge,  as  shown  in  Fig. 
88C^  is  t  named  a  commode  step.     A  step  'witiVv  \\>a  owXi^v  ^av\ife\ 


/ 


432      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

rounded  t«  a  quadrant  is  a  bulliune  step  ;  if  the  end  of  the  sUp 
is  semicircular  it  is  a  round-uidsd  step,  while  if  the  curved  end  is     ' 

somewhat  of  a  scroll  the  step  is  called  a  oortall  step. 

Distinctive  names  are  given  to  the  string  boards.  Forei' 
ample,  a  string  board  with  parallel  edges,  which  is  trenched  to 
receive  the  ends  of  the  treads  and  risers,  and  has  therefore  part 
of  its  width  above  the  steps,  is  called  a  dose  striiif; :  it  is  either 
the  will  siring  or  the  outer  {viell)  string,  accoi-ding  to  its  position. 
Tlie  outer  string  has,  in  some  types  of  stairs,  the  upper  edge  cpt 
to  the  prolile  of  the  treads  and  risers,  and  is  then  named  a  cut 
string.  With  a  cut  string,  the  ends  of  the  treads  overhang,  and 
have  mitred  and  returned  nosings  (Fig.  839) ;  the  risers  under 
these  treads  may  have  the  ends  mitred  to  the  string  boards,  or 
thin,  shaped  brackets  may  be  mitred  against  the  ends  of  the 
risers,  the  object  being  in  either  case  to  avoid  showing  the  end 
of  the  riser.  The  former  of  these  cut  strings  ia  called  a  cM 
and  mitred  Etring',  and  the  latter  a  bmcketad  string  (Fig.  S48). 
With  some  types  of  atairs  it  is  necessary  to  have  the  outer 
string  constmcted  to  turn  through  an  angle  at  the  change  of 
direction  of  the  stairs ;   such  a  string  is  named  a  wiMtHd 

Stairs  more  than  3  feet  wide  should  be  supported  upon  inclined 
wooden  carriaeeB  consisting  of  rough  quartering.  Triangulai 
blocks  placed  upon  the  upper  edge,  or  rough  cleatn  nailed  (to  tie 
sides  of  these  carriages,  support  the  treads  ;  the  jiLinterei 
are  nailed  to  the  under  sides  when  a  plastered  soffit  i,i  )-eqliir«l. 

Wben  all  the  treads  are  rectangular  and  of  tho  Hame 
stairs  constitute  a  straUfht  flight.  When  windors  arE' 
turn  through  a  light  angle,  the  stairs  are  described  a 
stairs.  When  the  change  of  dnection  extends  thioughl  tfO 
right  angles,  futh  a  landing  between  the  two  flights,  the 
flight  ia  named  the  return  flight  Stairs  bavins;  return  1^ 
ai'e  called  dog-l^ged  when  the  width  of  each  flight  ii 
half  the  width  of  the  staircase,  and  the  outer  strings  of  tl 
flights  are  in  the  same  vertical  plane.  When,  on  the  other  M 
the  width  of  the  staircase  ia  more  than  double  the  widthM 
stairs,  it  allows  of  an  open  space  between  successivt!  fligbtM 
space  is  called  the  welL  When  there  are  posts  (newe 
at  the  angles,  the  stairs  are  called  open  newel  stairs. 
there  are  no  newel  posts,  and  the  outer  string  and  tb(>  'wiuii^ 
are  continuous  from  bottom  \a  Ui^,  Cat  aXaw-a  itt  «j:\\    \jjj! 


STAIRCASE  WORK  AND  HANDRAILING.  4.^ 

geometrical  Geometrical  stairs  may  be  arranged  in  either  a 
rectangular,  polygonal,  circular,  or  elliptical  staircase,  and  are 
iisually  named  accordingly. 

The  triangular  framing  placed  under  the  outer  string  of  a 
flight  of  stairs  is  called  the  spandrel  frnmiTig 

General  Principles  of  Stair  Construction.— In  superior 
dwelling-houses  and  in  public  buildings  it  is  usual  to  make  a 
special  feature  of  the  staircase  and  stairs.  In  cottages,  however, 
the  space  is  generally  too  limited  to  allow  much  scope  in  this 
respect.  In  planning  the  stairs  the  following  important  points 
need  attention.  The  staircase  should  be  well  lighted.  The 
stairs  should  be  arranged  in  straight  flights  of  not  more  than 
twelve  steps  each,  and  all  steps  in  the  same  flight  must  have  an 
equal  rise.  If  the  height  from  flooi*  to  floor  renders  more  than 
twelve  steps  necessary,  there  should  be  a  landing  between 
successive  flights.  A  single  step,  or  a  combination  of  two  steps 
only,  between  adjacent  flights  is  objectionable  ;  winders  should 
be  avoided  as  far  as  possible,  although  by  their  use  a  saving  in 
space  can  be  effected.  When  winders  must  be  used,  they  should 
be  arranged  so  that  in  the  middle  o£  their  length  in  narrow 
stairs,  and  at  about  18  inches  from  the  handrail  in  wide  stairs, 
the  width  of  tread  is  equal  to  that  of  a  flier.  It  is  usual,  how- 
ever, to  arrange  three  winders  to  turn  through  a  right  angle 
(Fig.  873). 

To  economise  space  on  the  landing  of  the  upper  floor,  the  floor 
joists  are  trimmed  so  that  part  of  the  floor  overhangs  the  lower 
flight  of  stairs.  In  arranging  the  trimming  joists  it  is  necessary 
to  provide  headroom,  that  is,  sufficient  space  between  the  stairs 
and  the  under  side  of  the  upper  floor  to  allow  persons  to  ascend 
and  descend  the  stairs  without  stooping.  A  usual  distance  to 
allow  for  headroom  is  about  6'  6'',  measured  vertically  in  line 
with  the  face  of  the  risers.  Special  consideration  needs  to  be 
given  to  the  positions  of  doorways  and  windows — on  both  the 
upper  and  lower  floors — as  they  often  introduce  difficulties  in 
the  planning  of  the  stairs.  As  the  space  beneath  the  stairs  is 
almost  invariably  used,  either  as  an  approach  to  the  cellar  or  as 
a  storage  room,  any  landing  between  two  flights  should  be  high 
enough  to  allow  of  a  passage  under  it. 

Proportion  of  Tread  and  Riser.— The  width  of  the  tread, 
the  amount  of  rise,  and  the  proportions  between  these  are  of 
paramount  importance.    A  good  proportion  ioT  «Ji  «ajer3-^<5«^'^ 

M.C.J,  2  E 


434       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

stair  is  to  have  a  tread  1 1  inches  wide  (neglecting  any  over- 
hanging nosing)  and  a  rise  of  6  inches.  These  dimensions 
when  multiplied  together  equal  66  ;  it  will  be  found  a  satis- 
factory guide  to  take  this  number  as  a  constant,  and  the 
following  formula  can  be  used  : — 

tread  X  rise =66. 

From  this  it  will  be  seen  that  a  5^  inch  rise  will  need  a  12 
inch  tread,  while  a  rise  of  7  inches  will  require  a  tread  ^ 
inches  wide. 

Another  rule,  which  also  gives  satisfactory  results,  is  to  make 
the  width  of  the  tread,  pliis  twice  the  height  of  rise,  equal  to  23 
inches.  This  can  be  expressed  as  follows  : — If  T=  width  of  tread 
in  inches,  i2= height  of  rise  in  inches,  then 

r+2/2  =  23  inches. 

Although  limitations  of  space  often  prevent  the  construction 
of  an  ideal  stair,  care  should  be  taken  to  make  the  best  of  the 
available  space,  especially  as  a  badly  designed  and  pi'oportioned 
stair  is  not  only  fatiguing,  but  a  serious  danger  to  the  safety  of 
old  people  and  young  children.  For  a  dwelling-house  the  stairs 
should  be  from  2'  6"  to  3'  wide,  with  a  rise  of  from  6^  to  8 
inches,  and  a  proportionate  width  of  tread.  For  public  build- 
ings, the  width  of  the  stairs  varies  from  3  feet  to  6  or  even 
8  feet,  and  the  rise  is  from  5  to  7  inches. 

The  Setting-out  ^f  Stairs. — It  is  reasonable  to  assume  that 
the  type  and  general  arrangement  of  the  stairs,  with  the 
positions  of  start  and  finish,  landings,  winders  (if  any),  adjacent 
doorways,  etc.,  have  all  been  considered  during  the  pre- 
paration of  the  designs  and  general  plans  of  the  building. 
It  is  the  joiner's  duty  to  "set  out"  and  construct  the  stairs 
from  drawings  supplied  to  him  which  embody  the  points  just 
mentioned.  The  first  thing  to  do  in  the  construction  of  a  flight 
of  stairs  is  accurately  to  measure  the  staircase,  test  the  angles, 
and  to  draw  to  scale  a  plan  showing  the  amount  of  space  avail- 
able and  the  exact  positions  of  any  doorways  or  windows  in 
close  proximity. 

The  plan  of  the  staircase  having  been  drawn,  it  will  be 
necessary  to  determine  the  number  of  steps  required  to  ascend 
from  the  lower  to  the  higher  floor-level.  To  do  this,  the  height 
from  floor  to  floor  must  be  obtained.  It  is  usual  to  employ  for 
this  purpose  a  storey  rod,  tYiat  is,  %.  to^  «i\>o\x\i  \^  \\\q\v^<^  «\jiare 


STAIRCASE  WORK  AND  HANDRAILING. 


435 


y  \ 


and  long  enough  to  reach  from  floor  to  floor.  It  must  be  borne 
in  mind  that  in  each  flight  there  is  one  more  riser  than  tread, 
owing  to  the  landing  on  the  upper  floor  serving  the  purpose  of 
a  tread.  J  By  applying  the  rule  previously  given  of  the  pro- 
portion of  tread  to  riser,  it  remains  to  be  decided  what  the  rise 
shall  be.  For  example,  if  the  height  from  floor  to  floor  measures 
10'  6",  and  there  is  plenty  of  "  going  space  "  in  the  staircase,  a 


.Yp><>^^>^>^y>^^^^>^^^^>^^^^ 


Sa 

I 

i 

! 

I 
I 

I 


Ha  IP  Space 
Landing 


44-0 


-M- 


-tt- 


-M- 


-le- 


-6- 


-4- 


■4- 


"«- 


-»l- 


-th 


■%*■ 


-Gft- 


mfliffin  ^ 


Landing 


Fig.  841. 


Fio.  840. 


:y 


Alternative  Plans  of  Dog-legged  Stairs. 


rise  of  6  inches — which  would  give  an  easy  stair — might  be 
adopted  :  this  would  require  21  risers,  and  20  treads  each 
11  inches  wide.  On  the  other  hand,  assuming  that  the  going 
space  is  more  limited,  while  the  height  is  still  10'  6",  a  greater 
rise  and  a  narrower  tread  will  be  necessary.  A  rise  of  more 
than  8  inches  is  not  desirable,  so  that  it  is  necessary  to  find  a 
height  between  6  and  8  inches  which  will  divide  without  re- 
mainder into  the  total  height  (lO'  6").  The  number  of  risers  thus 
obtained  will  obviously  lie  between  ^g^  {i.e.  21)  and  ^Jf^  (i.e.  15|). 
It  may  be  1 6, 1 7,  ]  8, 1 9,  or  20,  with  correapot\d\t\^TO^^  ^^^  =^'^  \ 


436       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

W  =  ^vr"  ;  W = *7",  etc.  Although  the  rise  of  71"  does  not  give 
a  very  easy  stair  it  is  often  adopted  where  space  is  limited. 
The  rise  having  been  decided  upon,  the  width  of  tread  is  found 
by  the  rule  given  on  p.  434.     With  a  rise  of  7f "  the  tread  will  be 

?|=8/r '  (approximately  8f").     Figs.  840  and  841  show  plans  of 

'8 


H-  Widrh   of  Tread 


I/) 

o 


0       » 


Pirch  Board 


Fig.  842. 


Fig.  843. 


the  two  stairs  just  described.  In  the  former,  21  risers  are  shown, 
the  stairs  being  in  two  flights  with  a  half -space  landing.  In  the 
latter,  winders  and  a  quarter-space  landing  are  shown  at  the 
change  of  direction.  These  two  illustrations  are  introduced 
mainly  to  show  the  difference  in  the  space  occupied,  with  what 


Fig.  844.— Method  of  "  settiiig-out "  a  String  Board. 

may   be   considered  the  two   extremes   of  rise   for   the   stairs 
of  dwelling-houses. 

The  plan  of  the  stairs  having  been  completed,  it  is  necessary 
to  prepare  a  pitch  board  and  three  templates.  A  pitch  board  is 
a  thin  triangular  board  ;  two  of  the  sides  of  the  triangle  contain 
a  right  angle,  and  are  of  length  equal  to  the  rise  and  the  width 


STAIRCASE  WORK  AND  HANDRAILING  437 

of  the  tread  respectively  (Fig.  842).  The  margin  template  (Fig. 
843)  is  used  along  with  the  pitch  board  in  marking  out  upon 
the  string-boards  the  positions  of  the  trenches  for  the  treads 
and  risers  as  indicated  in  Fig.  844.     The  other  templates  (Figs. 

845    and    846)   are   used   for 


^.  ^     ^1  ..  A     marking   the    widths  of    the 

Riser  Templafc     B     ^        ,^.      ,,      , 

-^ — z^.z-z.zjL.Z^ — I V     trenches  for  the   tr* 


eads   and 

Fio.  845.  risers     respectively.        With 

close  strings,  the  distance  of 
the  line  of  nosings  (p.  430)  from  the  upper  edge  of  the  string 
is  from  '2^"  to  S^'\  and  the  setting  out  of  the  trenches  is 
done  from  the  upper  edge.  The  width  of  the  string  varies 
from  9  to  12  inches ;  it  is  governed  by  the  inclination  of  the 
stairs.  It  should  be  noticed  that  the  two  strings  for  the  same 
flight  must  be  set  out 

in  pairs  and  in  setting     /'= Tread  Template  ^ 

out  winders,  the  direc-     ^ — , . 

tion  in  which  the  stairs  Fio.  846. 

turn  must  be  borne  in 

mind.     When  winders  are  used  it  is  well  to  draw  a  full-sized 

plan  of  these,  in  order  to  obtain  the  exact  widths  of  the  ends 

of  the  winder  treads  ;  and  as  they  are  wider  than  the  fliers,  the 

wall  strings  supporting  them  require  to  be  wider  than  in  the 

remaining  part  of  the  stairs,  as  shown  in  Figs.  869  to  873. 

Joints  between  Treads  and  Risers.— 
The  edge  Joints  between  the  treads  and 
risers  may  be  square,  or  they  may  be 
tongued  and  grooved.  It  is  only  in 
the  commoner  kinds  of  stairs  that  the 
edge  joints  are  square  as  shown  in  Fig. 
847,  since  square  joints  allow  of  dirt 
getting  through  them.     Fig.  862  shows 

^'°*  TJ^^!ndRi^or''^^     ^^e  lower  edge  of  the  riser  tongued  to 

fit  into  a  groove  in  the  upper  side  of 
the  tread.  The  upper  edge  of  the  riser  is  square,  and  fits 
against  a  rebate  formed  by  having  a  moulded  fillet  tongued 
into  the  underside  of  the  nosing  edge  of  the  tread.  Fig.  863 
shows  an  alternative  method  of  arranging  the  joints  between 
the  treads  and  risers.  These  joints  are  not  so  good  as  those 
shown  in  Fig.  862  ;  it  will  be  seen  that  the  groove  on  the 
lower  edge  of  the  riser  is  a  source  of  weakness.      The  joints 


438      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

are  secured  by  nailing  or  screwing  them  together  ;  they  are 
further  strengthened  by  glueing  wooden  blocks  in  the  angles 
(Fig.  864). 

Types  of  String-board.— When  dose  striiisr-boards  are  used, 
the  ends  of  the  treads  and  risers  are  housed  for  about  half 


A 

^      Bracket -K 


Section  on 
CD 


"^^Brackcr 
Section  on  AB 

Fig.  848. — Details  of  part  of  a  Bracketed  Stair. 

an  inch  into  trenches  cut  into  the  face  of  the  strings  (Fig.  864). 
These  trenches  are  cut  wider  than  the  thickness  of  the  treads 
and  risers  to  allow  of  the  insertion  of  tapei'iiig  wedges,  which 
are  glued  and  driven  in  at  the  back,  and  hold  the  stairs 
together.  Nails  are  often  driven  through  the  wall  strings  into 
the  ends  of  the  treads  and  risers,  and  in  addition  glue-blocks 
are  placed  in  all  the  aug\ea  on  \\ia  wtA^y  ^\Oife  c»1  \>cv»i  ^\a:vc>s». 


STAIRCASE  WORK   AND  HANDRAILING. 


439 


Although  the  wall  strings  are  almost  invariably  close  strings, 
th«  outer  string— especially  in  geometrical  atairs^is  either  cut 
and  mltted,  or  out  and  bracicetea  When  close  strings  are  used 
for  both  sides  of  the  stairs,  the 
treads  (fliers)  and  the  I'isers  under 
them  are  all  cut  to  the  same  length 
and  the  ends  left  square.  With  a 
cut  string,  the  outer  ends  of  the 
treads  a,ve  mitred,  and  a  narrow  nos- 
ing ia  returned  around  the  end  (Fig. 
839).  If  the  risers  are  mitred  to  the 
string,  they  are  cut  aa  shown  in 
Fig.  839.  Fig.  848  shows  the  details 
of  the  ends  of  two  steps  which  are 
finished  with  brackets  and  returned 
treads.  It  will  be  noticed  that  the 
ends  of  the  risers  are  mitred  to  the 
brackets,  the  object  being  to  avoid 
showing  the  end  grain  of  the  wood 
The  lower  ends  of  the  vertical 
balusters  which  support  the  hand 
rail  rest  upon  the  ends  of  the  treade, 
and  are  secured  by  being  dovetailed 
into  them  as  shown  in  Fig.  839 

The  outer  strings  in  newelled  stairs 
hav*  the  ends  tenoned  into  the  neuel 
posts  as  shown  in  Fig.  R49.  The 
newel  post  may  extend  to  the  floor, 
and  thus  act  as  a  support,  or  it  may 
finish  a  little  below  the  ceiling  level 
of  the  stairs,  with  a  turned  or  carved 
terminal  called  a  drop.  Any  treads 
or  riaeia  which  abut  on  the  newel 
posts  are  genei-ally  housed  into  the 
posts  as  shown  in  Fig.  S49.  The 
angle  joints  of  wall  strings  a 
tongued  and  grooved,  and  the  i 
"  eased  "  to  correspond  in  width  with  the  skirting  board  (E^ga. 
869  and  870) ;  the  mould  of  the  skirting  being  continued  along  the 
up|)er  edge  of  the  string-board.  A  close  outer  string  is  usually 
earmauaCed  hy  a  moulded  citp^i\g,  u.poTi  'wVvAi  ^^ftVi-Kes  tto&a. 


Treada,  Blacrs, 


a   Strioga, 


and  lower   ends 


440       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

of  the  baluEterR  are  fixed  (Fig.  875),  and  the  outer  side  of  thit 
string  may  be  panelled  or  ornamented  by  sunk  mouldings. 

A  wreatlied  Etilng  (the  outer  string 
of  a,  geometrical  atair)  may  have  the 
curved  part  constructed  in  sever^ 
different  ways.  When  the  well  iaof 
siLiall  Tadiua  and  the  outer  surface  of 
the  string  has  deep  sunk  mouldiii|s, 
the  cui'ved  part  of  the  string  may 
be  built  up  by  glueing  togetler 
narrow  pieces  with  cross-tonguea  in 
the  joints,  an  shown  in  Fig.  850 ;  this 
construction  is  known  as  a  itatti 
well.  Another  way  is  to  reduce  the 
thickness  of  the  curved  part  of  the  string  toa  veneer,  and  block 
the  back  side  of  the  veneer  with  rilis,  the  grain  of  which  ia 
vertical  (Fig.  851).  Stout  can- 
vas giued  on  the  ribs  is  an 
additional  source  of  strength. 
Such  a  veneered  string  is  gener- 
ally considered  better  than  a 
staved  string.  With  wells  of 
large  radii,  or  in  stairs  the 
strings  of  which  form  a  con- 
tinuous curve  {e.g.  geometrical 
stairs,  either  circular  or  ellipti- 
cal), the  outer  strings  are  usually 
built  up  by  glueing  and  screwing 
together  sevei-al  layers  (laminae) 
of  thin  boards  with  overlapping 
joints.  The  resulting  string  is 
called  a  laminated  string.  The 
two  methods  last  named  require 
a  semi -cylindrical  block  (or,  in 
the  case  of  a  circular  well,  a 
complete  cylinder)  of  radius 
equal  to  the  radius  of  the  well 
of  the  stairs,  round  which  the  ve 
and  temporarily  held  until  the  g 

The  method  of  ascertaining  the  shape  to  which  the  veneer  for 
a  wreathed  string  must  be  cut  ia  s^vo-w^  \ti  Y\?,a.?fti^  Xo  «&?>. 


r  thin  layers  are  bent 


STAIRCASE  WORK  AND  HANDRAILING. 


441 


plan  of  the  curved  part  of  the  string  is  first  drawn /mW  size^ 
on  it  are  marked  the  intersections  of  the  veneer  and  the 
.  ,of  all  the  risers.  The  next  thing  to  be  done  is  to  draw 
"stretch-out"  (development)  of  the  curved  surface  repre- 
3d  in  plan.     The  length  of  the  curved  lines  A^B^C,  etc. 


** . 


frijasiy 


Fig.  852. 


Fio.  858. 


Method  of  development  of  a  Veneered  String  Board. 

.  853),  are  of  course  the  widths  of  the  treads  where  these 
i-sect  the  veneer.  The  risers  are  all  equal.  The  soffit 
e  of  the  veneer  is  drawn  parallel  to  the  line  of  nosings. 
854  shows  the  development  of  the  veneer  for  the  wreathed 
ig  of  a  geometrical  stair  with  six  windei's  used  to  turn 
ugh  two  right  angles,  as  shown  in  Fig.  883. 
mstruction  of  Steps  with  Bent  Risers.— The  risers 
yuYl-nose,   round-ended^  and    curtail   atei^a    \i^v^    <i\3ccN^ 


442       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

surfaces.  A  general  method  of  construction  is  to  cut  the  naen 
out  of  a  board  of  the  same  thickness  as  the  other  risers,  and 
reduce  to  a  veneer  the  part  which  has  to  be  bent  round  the 
curved  surface.  A  solid  block  of  the  required  curvature,  built 
up  of  several  thicknesses  of  material,  with  the  grain  crossing 
is  prepared,  round  which  the  riser  is  bent  and  secured  with 


tl  JasQi 


Fig.  854. 


Fio.  855. 


Method  of  development  of  a  Veneered  String  Board. 


glue,  wedges,  and  screws.  Figs.  856  and  857  show  a  bull-nose 
step  ;  Figs,  858  and  859  show  a  round-ended  step  ;  and  Figs. 
860  and  861  show  the  method  of  construction  for  a  curtail  step. 
The  outline  foi*  a  curtail  tread  corresponds  to  that  of  the  hand- 
rail scroll  above  it  (Fig.  880).  It  will  be  noticed  that  the  small 
mould  under  the  nosing  of  the  tread  is  worked  out  of  the  solid, 
and  is  placed  between  the  tread  and  the  upper  edge  of  the 
riser  (Fig.  861),  thus  reducing  the  width  of  the  latter.  This 
method  gives  much  better  results  tha.u  would  be  obtained  from 


STAIRCASE  WORK  AND  HANDRAILING.  443 


'Sect'lon  'thraugti  A*B . 


1  aud  Boctlon  of  s  Rnunia-oi: 


-  Srnng  board 


r       ^         Weflge  d 

Plan  oF  Riser 

Fia.  860. 

Details  of  a  Curtail  Stsp. 


444       A  MANUAL  OF  CARPENTRY  AND  JOINEKY. 

an  attempt  to  bend  the  small  mould  round  the  curve.  Tk 
riser  for  a  commode  step,  the  whole  length  of  which  is  curved 
(Fig.  880),  may  either  be  constructed  out  of  an  inch  board 
having  saw-cuts  in  the  back  side  to  allow  of  bending  (p.  471) ; 
or  it  may  consist  of  a  thin  veneer  which  is  glued  and  screwed 
to  shaped  blocks. 

Landings  and  Carriages.— A  quarter  or  balf-spaoe  landing 
for  stairs  is  constructed  as  a  small  floor,  as  much  support  as 
possible  being  obtained  by  building  the  ends  of  the  joists  into 
the  wall.  These  joists  being  of  short  bearing,  do  not  require  to 
be  so  strong  as  ordinary  floor  joists  ;  they  are  usually  from  4  to 
6  inches  deep,  and  3  inches  thick.  The  tusk-tenon  joint  is 
the  best  joint  to  use  at  the  ends  of  all  joists  abutting  against 
the  trimmer.  Additional  support  is  often  given  to  the  outer 
corner  of  a  quarter-space  landing,  by  allowing  the  newel  post  to 
extend  to  the  floor.  The  same  support  may  be  obtained  by 
having  a  strong  corner-post  against  the  spandrel  framing ;  this 
post  often  serves  as  part  of  the  door  framing  when  a  door  is 
placed  adjacent  to  the  spandrel  framing. 

For  stairs  more  than  three  feet  wide,  it  is  advisable  to  have     i 
rou^h  carriages  as  an  additional    means  of  support.      These 
carriages  are  about  5  inches  deep  and  3  inches  thick.    They 
extend  from   the   floor  to   the   landing,  and   forward  to  the 
upper  floor,  and  are  inclined  so  that  the  steps  rest  upon  them. 
By  securing  them  to  the  floor  and  to  the  landings,  additional 
strength  is  given  to  the  latter,  while  the  treads  receive  further 
support  by  cleats  nailed  to  the  aides  of  the  carriages,  as  shown 
in  Fig.  862.     With  some  types  of  geometrical  stair  considerable 
skill  is  required  to  ai-range  the  carriages  in  the  best  positions. 
An  alternative   to   the  carriages  above  described  is  to  have 
triangular  blocks,  from  2  to  3  inches  thick,  glued  and  screwed 
together  in  a  continuous  line  under  the  middle  of  the  treads 
as  shown  in  Fig.  863. 

The  trimming  joists  of  an  upper  floor  landing,  which  form 
the  sides  of  the  well,  require  facing  to  match  the  stairs. 
This  may  be  done  with  either  plain  or  panelled  facing-boards. 
The  boards  used  must  be  a  little  wider  than  the  joists,  so  that 
their  lower  edges  finish  flush  with  the  plaster  ceiling.  Such 
facing-boards  are  called  apron  linings. 

Erection  of  Stairs. — ^The  actw^il  i^wttm^  to^^ather  of  a  flight 
of  stairs  is  done  as  far  aa  po^WAev  Vu  \i\i^  -wotV^o^,   ^XjwCv^^ 


STAIRCASE  WORK  AND  HANDRAILING. 


445 


lights  present  no  difficulty  in  this  respect ;  with  stairs  having 
winders,  however,  their  bulkiness  when  completed,  and  often 
tbe  limited  space  in  which  they  are  to  be  placed,  renders  it 


Carriage^ 


PiQ.  862. 


Blocks  2^ 


Pio.  863. 
Sections  through  the  Steps  of  Stairs. 


necessary  to  fix  the  winders  after  the  straight  parts  have  been 
fixed  in  position. 
Assuming  that  the  string  boards  have  a\\  b^^ii  Vc'Kti.Osi'^^ 


446       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

with  the  necessary  easiogs  along  the  edges  ;  that  the  treads  and 
risers  have  been  trued  up,  nosed,  tongued  and  grooved,  and 
smoothed  off:  it  is  usual  first  to  fasten  the  treads  and  nsen 
together  in  pairs.  A  handy  workshop  appliance  called  a  cradle 
is  used  for  this  purpose.  The  steps  are  then  fitted  into  the 
trenches  in  the  strings  and  numbered,  and  are  finally  put 
together  with  the  aid  of  specially  devised  cramps.  The  taper- 
ing wedges  which  are  used  for  securing  the  ends  of  the  steps 
are  then  glued  and  driven  into  position.     It  will  be  noticed 


Fig.  864.— Sketch  of  part  of  a  Flight  of  Stairs,  showing  the  method  of  Wedging 

aud  ]31ockiiig  together  the  various  parts. 

that  these  wedges  are  driven  in  at  the  back  sides  of  the  treads 
and  risers  (Fig.  864),  and  that  as  they  are  driven  they  tend  to 
close  all  the  joints  between  the  face  of  the  string  and  the  steps, 
and  also  the  joints  between  the  edges  of  the  treads  and  risers. 
The  edge  joints  are  also  screwed  together  and  glue  blocks 
inserted  in  all  internal  angles  on  the  under  side  of  the  stairs. 


TYPES  OF  STAIRS. 

The  foregoing  description  of  stairs  is  of  general  application, 
and  covers  the  work  to  a  considerable  extent.  As,  however, 
each  different  arrangement  has  peculiarities  of  its  own,  it  will 
now  be  well  to  glance  at  these  in  detail. 


TYPES  OF  STAIRS. 


447 


Straight  Flight. — The  simplest  kind  of  stairs  is  one  much 
used  in  warehouses,  workshops,  etc.,  where  the  available  space 
is  very  limited.  These  stairs  have  no  risers.  The  ends  of  the 
treads  are  tightly  housed  into  the  string  boards,  and  are 
secured  by  nailing.  The  stairs  are  strengthened  by  passing 
bolts  through  the  strings  from  side  to  side,  just  under  every  fifth 
or  sixth  tread.     Both  the  treads  and  the  string  boards — often 


Secrion  on  AB 

Fig.  865. 


Section  on  A-B 

Fig.  867. 


S-^*! — ?— S 


♦— -^ — Q   q    q — • 


1        <= 


-%     A- 


o         <= 


Plan 

Fig.  806 


Plan 

Fig.  868. 
Types  of  Straight  Flights  of  Stairs. 


called  notch  boards  in  such  stairs— are  thicker  than  those  of  stairs 
which  have  risers.  Figs.  865  and  866  show  sectional  elevation 
and  plan  of  such  stairs.  It  will  be  seen  that  the  front  edge  of 
each  tread  overhangs  part  of  the  next  tread  below  it ;  by 
this  means  a  considerable  amount  of  going  space  is  saved. 
This  type  of  stair  is  improved  by  boarding  the  back  or  under- 
side of  the  notch  boards  with  tongued  and  grooved  match 
boarding. 
Figs.  867  and  868  show  sectional  e\evat\otv  ww^k  -^^rsi  ^1  ^ 


tbruugli  a  tigLt  ajiglo. 


TYPES  OF  STAIRS.  449 

/raight  flight  of  stairs  with  treads  and  risers,  the  rise  being  the 
inie  as  in  Fig.  865.  A  comparison  of  the  two  examples 
aows  that  much  more  horizontal  distance  (going  space)  is 
ecessary  in  Fig.  867  than  in  Fig.  865. 

Stairs  with  Winders. — Figs.  869  to  873  illustrate  details  of 
»art  of  a  flight  of  stairs  often  found  in  cottages  and  other  small 
Iwelling-houses.  The  arrangement  shows  three  winders  used 
o  turn  through  a  light  angle  to  the  right.  The  outer  angle  is 
lupported  by  a  newel  post  which  extends  from  floor  to  floor  ;  it  is 
nortised  to  receive  the  ends  of  the  outer  strings,  and  trenched  for 
)he  abutting  treads  and  risers  as  shown  in  Fig.  849.  Such  stairs 
ire  often  enclosed  by  fixing  one-inch  tongued  and  grooved  match 
Doarding  against  the  sides  of  the  outer  strings,  vertically  in  line 
5nth  the  newel  post.  Figs.  869  and  870  show  the  wall  strings  for 
)hese  stairs  with  the  trenches  and  joint-lines  marked  thereon, 
rhe  lengths  of  the  trenches  for  the  ends  of  the  winder  treads 
ire  obtained  from  the  plan,  as  shown  in  Fig.  873.  In  this  type 
►f  stairs  close  strings  are  used  on  both  sides.  The  ends  of  the 
vail  strings  which  fit  together  have  a  tongued  and  grooved 
oint,  are  nailed  together  at  the  angle,  and  are  secured  to  the 
vail  by  being  nailed  to  plugs  driven  into  the  joints  of  the 
)rickwork.  It  gives  additional  security  if  a  joggle,  left  upon 
he  end  of  the  upper  string,  fits  into  a  hole  cut  in  the  corner  of 
he  wall. 

Dog-legged  Stairs. — As  previously  stated,  a  dog-legged  stair 
s  one  in  which  the  change  of  direction  is  through  two  right 
ingles,  and  the  outer  strings  are  in  the  same  vertical  plane. 
Although  the  change  of  direction  may  be  effected  by  using 
svinders  only,  such  a  construction  is  not  advisable,  and  should 
3e  adopted  only  where  the  space  is  very  limited.  Figs.  840  and 
341  are  plans  of  two  examples  of  this  type  of  stair,  and  Figs. 
374  and  875  show  details  of  a  similar  stair  with  a  half-space 
landing  between  the  two  flights.  The  landing  is  placed  at  a 
convenient  height  to  allow  of  access  to  a  room  under  the  stairs. 
The  width  of  the  landing  is  equal  to  the  width  of  the  stairs,  the 
irrangement  of  the  joists  of  the  landing  and  the  carriages  being 
IS  shown  in  the  plan. 

Open  Newel  Stairs. — This  type  of  stair  has  a  well,  and  a 

lewel  post  at  each  angle.     Fig.  876  shows  the  plan  of  an  open 

lewel  stair  where  the  staircase  is  a  little  wider  than  double  the 

width  of  the  stair,  and  winders  and  a  quarter-space  landing  are 

M.C.J.  2  F 


« 

90 

A  MANUAL  OF 

CARPENTRY 

AND  JOINERY. 

1 

^^S#5Sst^^ 

■SSSJ*SSSS««SSJ^^ 

1 

-—it 
=-.=  --=ii 

ir 

F==-.3J 

- 

.^ 

-^- 

1!   !!  .          1 

-■ 

1 

I 

r; 

^ 

«km\^^^^^^^^^% 

Hi^^ 

TYPES  OP  8TAIES. 


4JS1 


used.  Figs.  877  and  878  are  respectively  the  plan  and  sectional 
elevation  of  an  open  newel  atair  in  a  rectangular  staircase, 
arranged  to  allow  of  ascent  being  made  in  easy  stagea  of  short 
flights  with  quarter-space  landings  between  them.  The  close 
outer  strings  are  in  this  example  shown  panelled  :  they  have  the 
ends  tenoned  into  the  newel  poata,  and  are  further  supported  by 
the  panelled  spandrel  ^^■ss5is^iaai^^^-^sssss^gm:»->g^ 
framing ;  the  carriages  y*' 
and  the  landings  are 
all  framed  together  as 
shown. 

Geometrical  Stairs. 
— A  geometrical  stair  is 
one  in  which  the  direc- 
tion is  through  one  or 
more  right  angles :   it 

has  a  continuous  outer      _        

atringf  as  well  as  a  con-  ^vST'S^^SSs^S^^^^^^^^?^^^^^^^^^^^?^^^^'^^^^ 
tinuOUS  handrail  with-  ^'^  8Tfl.-Plin  of  .»  Open  N=w=lled  Stolr. 
out  any  newel-posts.  This  type  of  etair  lenda  itself  to  consider- 
able variation  of  treatment,  being  applicable  to  any  shape 
staircase,  and  even  te  the  construction  of  self-supporting  stairs. 
A  circular  geometrical  stair  takes  up  less  space  than  any  other, 
and  is  often  constructed  in  stone  as  well  as  of  iron.  The 
struction  of  a  circular  geometiical  stair  involves  a  large 
of  labour,  as  the  string  boards  are  ail  wreathed.  Figs.  879  and 
880  show  sectional  elevation  and  plan  of  a  geometrical  stair  with 
a  half-space  landing.  The  outer  string  is  cut  with  mitred  and 
returned  treads  and  brackets.  A  number  of  the  lowest  treads 
are  arranged  as  balancing  treads  :  the  two  nearest  the  bottom 
are  commode  steps.  The  brackets  under  the  outer  ends  of  the 
balancing  treads  are  narrower  than  those  under  the  fliers. 
Fig.  881  shows  a  method  of  finding  the  shape  of  these  diminished 
brackets  by  what  ai-e  known  as  radial  ordinates.  Figs.  882  and 
883  show  plans  of  different  arrangements  of  geometrical  stairs. 

Handrails.— The  bandrall  is  a  rail  fixed  directly  over  the 
outer  string  board  ;  sometimes  also  against  the  wall.  Its  object 
is  twofold  :  to  act  as  a  protective  fence  and  as  an  aid  to  person'! 
ascending  or  descending  the  stairs.  A  handrail  fixed  against  r, 
wall  is  generally  supported  by  iron  wall  brackets,  which  are 
screwed  to  plaga  in  the  wall.     A  handrail  over  tte  .s*.!:™^ 


482       A  MANUAL  OF  CARPENTRY   AND  JOINERY. 


Details  ct  an  Open  Yl  e' 


TYPES  OF  STAIRS. 


464      A  MANUAL  OF  CABPEKTBY  AND  JOINERY. 

board  has  the  ends  tenoned  into  the  oewel-poats,  and  is 
further  supported  by  baliutWB,  ab  shown  in  Figa.  884  to  887- 
The  balusters  may  be  square, 
moulded,  or  turned.  The  newel- 
posta  may  be  moulded,  turned,  or 
otherwise  ornamented  by  being 
carved.  Considerable  varation 
exists  in  the  size  and  dewgos 
of  newel-posts  and  balusters,  as 
will  be  aeon  from  an  observation 
of  every-day  examples.  The  line 
of  the  handrail  is  parallel  to  the 


(ainiuB  shap. 

line  of  noting"?,  and 
IS  placed  at  a  height 
above  it  of  about  2  Ti' 
(measured  veitiL.iIly  in 
iine  with  the  face  of 
tlieiisei)  The  hand 
rails  of  dog  legged  and 
open  newel  ^taiis  ai'e 
generally  in  straight 
lengths,  with  the  ends 
tenoned  into  the 
newel-posts  A  hand 
rail  should  be  nf  such 
a  section  that  it  can  be 
easily  grasped.  Figs. 
888  to  891  are  typical 
the  underside  of  the  baii4rai.\  w  i-tooMfti,  mi6. 


TYPES  OF  STAIRS. 


log  ol  difforent  tjpea  ot  atrtng-boarS,  C».\«»'ibib,  ^W. 


TYPES  OF  STAIRS.  457 

placed  in  the  groove ;  this  bar  is  screwed  to  the  upper 
«nds  of  the  balusters  and  to  the  underside  of  the  handrail. 
Iron  balusters  are  often  inserted — one  in  every  seven — as 
a  means  of  giving  additional  rigidity  to  the  rail.  The 
handrail  is  often  curved  at  the  angles  of  upper  landings, 
when  turned  into  a  wall,  or  against  a  newel-post.  Figs.  893 
to  896  show  some  of  these  curves  with  their  distinctive  names 
appended. 

The  li6i£:lit  of  the  handrail  at  a  landlTig  should  be  greater  by 
about  half  a  riser,  than  at  the  inclined  part  of  the  stairs.  In 
geometrical  stairs,  where  it  is  continuous,  the  handrail  requires 
to  be  "  wreathed  "  at  the  change  of  direction.  The  preparation 
of  these  wreaths  is  the  most  difficult  part  of  the  stair-builder's 
work,  and  is  generally  deputed  to  the  specialist.  Satisfactorily 
to  explain  the  construction  of  wreaths  in  handrailing  would 
require  more  space  than  is  here  available.  Any  cursory 
treatment  would  be  unsatisfactory,  and  will  therefore  not 
bp  attempted.  It  remains  to  be  mentioned  that  any  joints 
in  handrails '  are  made  with  dowels  and  handrail  bolts  as 
shown  in  Figs.  888  and  892. 


Summaxy. 

Wooden  stairs  consist  of  string  hoards  supporting  horizontal  treads 
and  vertical  risers. 

StriDg  boards  may  be  close  (having  parallel  edges)  or  cut  (with  the 
upper  edge  cut  to  the  profile  of  the  steps). 

A  cut  string  may  be  ciU  and  mitred  or  ciU  and  bracketed. 

The  outer  curved  string  of  a  geometrical  stair  is  called  a  wreathed 
string. 

The  triangular  framing  under  the  outer  string  is  named  spandrel 
framing. 

When  the  successive  flights  of  a  stair  are  not  in  the  same  straight 
line,  the  change  of  direction  is  obtained  by  winders  or  by  landings — 
qtuirter-spa^ce  or  half-space  according  to  the  angle  between  the 
flights. 

Wide  stairs  require  further  supporting  by  rough  wooden  carriages 
upon  which  are  nailed  cleats  or  triangular  brackets. 

Useful  relative  dimensions  (in  inches)  of  the  width  of  tread  and 
height  of  rise  are  given  by  the  formulae  : 

rxJ?=66,  or  r+2JR=2.^ 


458      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

The  principal  types  of  stairs  are  Btraight  flig^ht^  stairs  witli 
winders,  dog-legged,  open  newel,  and  geometrical  The  two  last 
named  are  arranged  around  a  space  called  the  welL 

A  handrail  is  supported  by  vertical  balusters,  and  in  newelled 
stairs  has  its  ends  tenoned  into  newel  posts. 


Questions  on  Cliapter  ZVI. 

1.  Give  sketches  J  full  size  of  the  various  methods  used  in  the 
joint  between  riser  and  tread.  Also  explain  with  plan  (scale  J  in. 
to  the  foot)  the  use  and  meaning  of  the  term  "balancing  treads." 
(C.  andG.  Ord.,  1892.) 

2.  (a)  Make  a  drawing  of  the  end  of  a  curtail  step,  (b)  How  are 
treads  and  risers  secured  to  the  strings  in  the  case  of  both  cut 
string  and  close  string  ?    (C.  and  G.  Ord. ,  1899. ) 

3.  Explain  the  following  kinds  of  stair :  Dog-legged ;  newel ; 
geometrical;  dancing.     (C.  andG.  Ord.,  1896.) 

4.  The  stairs  of  a  cottage  have  to  be  arranged,  with  winders,  to 
turn  through  a  right  angle  to  the  right  when  ascending.  On  the 
lower  floor  there  is  a  doorway  4  ft.  9  in.  from  the  comer.  The 
stairs  are  to  be  2  ft.  9  in.  wide,  and  are  to  be  enclosed  with  1-inch 
vertical  tongued  and  grooved  match-boarding.  The  height  from 
floor  to  floor  is  9  ft.  9  in.  Make  all  the  necessary  working 
drawings  ;  scale,  for  plan  and  section  ^  in.  to  one  foot,  for  enlarged 
details  1^  in.  to  one  foot. 

5.  Explain,  with  sketches,  the  meaning  of  the  terms  wall  string, 
well  string,  close  string,  cut  string,  mitred  string,  bracket  string, 
wreathed  string.  Make  a  plan  and  section  of  a  dog-legged  stair- 
case ;  all  construction  to  be  shown.     (C.  and  G.  Ord. ,  1903. ) 

6.  Draw  the  plan  and  sectional  elevation  of  a  dog-legged  stair  in 
a  staircase  6  ft.  wide.  The  height  from  floor  to  floor  is  11  ft. 
Arrange  a  quarter-space  landing  and  winders  above  it  at  such  a 
height  that  headroom  for  a  passage  under  the  landing  is  obtained. 
Scale  f  inch  to  one  foot. 

7.  Make  plan  and  section  of  an  open  newel  stair,  having  winders. 
All  details,  such  as  strings  and  carriage  pieces,  are  to  be  shown. 
(C.  andG.  Ord.,  1902.) 

8.  Draw,  to  a  scale  of  ^  in.  to  a  foot,  a  plan  of  a  newel  staircase, 
3  ft.  6  in.  wide  ;  height,  floor  to  floor  12  ft.  ;  in  a  liall  9  ft.  wide. 
Explain  the  method  of  setting  out  this  stair,  and  how  you  would 
determine  the  proper  proportion  of  tread  to  risers.     (C.  and  G. 

Ord.,  1898.) 


QUESTIONS  ON  CHAPTER  XVI.  459 

9.  Draw,  to  a  scale  of  i  inch  to  a  foot,  in  plan  and  section,  a 
newel  staircase,  to  rise  12  ft.  from  floor  to  floor,  to  be  3  ft.  wide, 
and  to  be  contained  in  a  space  8  ft.  by  8  ft.     (C.  and  G.  Ord.,  1893.) 

10.  Draw  a  plan  and  sectional  elevation,  with  all  details  necessary 
to  show  the  construction,  of  a  geometrical  stair  3  ft.  6  in.  wide,  in 
a  staircase  7  ft.  9  in.  between  the  walls.  The  height  from  floor  to 
floor  is  12  ft.  Show  a  half-space  landing  at  about  8  feet  from  the 
lower  floor  level.     Scale  ^  and  (for  details)  J  full  size. 

11.  Make  a  drawing  of  a  geometrical  staircase  ;  all  details  should 
be  shown.     (C.  and  G.  Hon.,  1904.) 

12.  Draw  a  plan  of  a  geometrical  stair,  scale  1  in.  to  the  foot, 
and  give  full  details  of  the  construction  of  the  curtailed  step.  (C. 
and  G.  Ord.,  1901.) 

13.  Show  how  you  would  make  the  internal  string  of  a  geometrical 
stair.  The  well  hole  to  be  2  ft.  4  in.  in  the  clear.  (C.  and  G. 
Hon.,  1901.) 

14.  A  geometrical  staircase  has  a  veneered  string.  It  has  three 
winders  and  a  quarter-space  landing  at  one  part.  Well  hole  12 
inches  in  the  clear.  Work  out  to  a  large  scale,  the  development  of 
the  veneer  round  the  well  hole,  and  show  by  dotted  lines  the 
construction.     (C.  and  G.  Hon.,  1892.) 

15.  Draw  the  plan  and  show  the  construction  of  a  commode  step 
for  a  geometrical  stair ;  show  also  the  method  of  developing  the 
inside  string,  and  give  a  description  of  the  process  of  preparing  it. 
(C.  andG.  Hon.,  1903.) 

16.  Draw  a  plan  and  section  to  J  in.  scale,  showing  the  con- 
struction of  circular  geometrical  stairs  3  ft.  9  in.  wide,  in  a  circular 
space  10  ft.  in  diameter,  the  stairs  to  rise  to  a  landing  9  ft.  from 
floor  to  floor.     (C.  and  G.  Hon.,  1893.) 

17.  Make  the  drawing  of  a  scroll  wreath  for  a  curtail  step. 
(C.  andG.  Hon.,  1903.) 


CHAPTER  XVII. 

WOBKSHOP  PBACTICE   AND  SPECIAL 
CONSTBUGTIONS. 

The  detailed  consideration  of  the  methods  of  preparing  and 
fixing  the  varied  work  upon  which  the  carpenter  and  joiner  are 
engaged  will  now  be  considered  briefly.  Although  the  pre- 
ceding chapters  give  detailed  information  of  the  several  branches 
under  distinctive  headings,  there  are  many  points  of  importance 
which  demand  further  attention. 

Arrangement  of  Workshop. — Although  the  arrangement  of 
the  workshop  is  of  some  importance,  there  is  evidence  to  show 
that  in  a  large  number  of  cases  it  does  not  receive  the  amount 
of  consideration  which  it  merits.  An  up-to-date  workshop  is 
arranged  so  that  there  is  abundance  of  light,  an  economical 
utilisation  of  space,  with  sufficient  room  to  undertake  the 
different  kinds  of  work  that  come  to  hand,  and  convenience  for 
transference  of  the  work  to  and  from  the  machines  and  the 
benches. 

Benches  are  usually  from  9  to  12  feet  long  ;  they  may  be 
single  or  double,  according  to  the  space  available,  or  the  manner 
of  lighting  the  room.  When  the  workshop  is  in  an  upper 
storey,  as  is  often  the  case,  special  attention  should  be  given  to 
the  strength  of  the  floor,  in  order  to  minimise  vibration.  It  is 
economical  to  have  each  bench  fitted  with  an  instantaneous-grip 
vice,  and  a  tail  vice  will  also  be  found  useful.  The  space 
between  the  benches  will  depend  upon  the  available  accom- 
modation, but  at  least  2  feet  is  required  for  the  bench-way 
between  single  and  3  feet  between  double  benches.  When 
much  machinery  is  in  general  use,  it  is  better  to  have  separate 
rooms  for  machinery  and  bencYiea,  aa  ^J^lfe  ^xxsX.  ^\v\Ocv  '\^  nwv- 


WORKSHOP  PRACTICE.  461 

avoidable  in  the  machine-room  will  interfere  with  the  cleanliness 
of  the  finished  work,  and  the  noise  and  vibration  often  detract 
from  the  accuracy  necessary  at  the  benches.     It  is  essential  that 
the  workshop  be  kept  clean  and  well  ventilated,  and  it  should 
be  provided  with  artificial  heat  in  the  winter  months,  as  well 
for  the  comfort  of  the  workman  as  for  the  sake  of  the  material. 
Side  lights  are  much  better  for  lighting  the  workshop  than  roof 
lights,  and  the  benches  should  be  arranged  with  the  head  ends 
to  the  light.     When,  as  is  often  the  case,  the  machine-room  is 
below  the  workshop,  a  trap  dqor  in  the  floor  of  the  latter  will 
be  found  a  necessity,  while  easily-ascended  stairs  are  indispen- 
sable.    The  artificial  lighting  of  the  room,  the  arrangement  for 
heating  the  glue,  the  position  of  the  grindstone,  and  the  storage 
arrangements  for  templates,  cramps,  and  sundry  appliances  in 
occasional  use,  all  demand  careful  consideration. 

"  Trueing-up "   of  Material.— As   has    been    explained    in 

Chapter  VI.,  machinery  is  used  very  extensively  for  cutting 

up  and  preparing  material.     Not  only  is  machinery  commonly 

used  to  "dress"   (plane)   to   the    exact    size    all    the   "stufi"" 

required,  but  any  grooving    of    the    edges,    or    rebating    or 

moulding    of    the    arrises   is   also    done    by   machinery,   and 

mortising  and  tenoning  machines  are  used  for  cutting  mortises 

and  tenons  ;  so  that  in  addition  to  the  setting-out  of  the  work, 

it  is  only  necessary,  in  the  mass  of  ordinary  framing,  for  the 

workman  to  examine  and,  when  necessary,  to  trim,  the  joints, 

and  to.  put  the  framing  together  and  smooth  it  off. 

When  the  trueing-up  of  the  material  for  framing  is  carried 
out  entirely  by  hand  labour,  care  must  be  taken  to  have  each 
separate  piece  planed  perfectly  true,  with  the  edges  straight  and 
at  right  angles  to  the  sides.  Unless  this  is  done  the  resulting 
framing  will  have  a  "  twisted  "  surface.  In  sawing  out  material 
which  has  to  be  hand  dressed,  it  is  necessary  to  allow,  over  the 
finished  sizes,  about  one  eighth  of  an  inch  in  both  width  and 
thickness  for  planing. 

In  dressing  the  material,  the  workman  uses  distinctive  marks 
for  what  he  considers  the  best  side  and  edge  of  each  piece. 
These  marks  are  named  face  marks,  and  they  play  an  important 
part  in  guiding  the  several  operations  through  which  each  piece 
has  to  go.  He  first  examines  the  piece  and  selects  its  best  side, 
dresses  this  side  until  a  truly  plane  surface  (which  is  tested 
with  the  winding  strips  (p.  108)  and  straight  ^^^fe'^K^  ^Xaks^fc^., 


462      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

and  then  puts  on  the  face-side  mark  a)  which  points  towards 

the  best  edge.  He  then  planes  the  best  edge  until  it  is  straight 
and  at  right  angles  to  the  face  side,  and  then  puts  on  the  face- 
edge  mark  A-  The  material  is  next  gauged  with  the  marking 
gauge  (p.  109)  to  the  required  width,  and  planed  to  this 
width  ;  after  which  it  is  gauged  to  the  required  thickness  and 
planed  to  this  thickness.  Of  course,  the  above  description  of 
trueing-up  work  applies  only  to  stuff  which  is  required  to  be  of 
definite  finished  size,  such  as  the  panelled  framing  of  doors, 
dado-framing,  bath  and  lavatory  fittings,  office  screens,  the 
framing  of  sashes,  etc.  Other  material  often  needs  only  to  have 
the  surfaces  dressed,  with  no  particular  care  as  to  straightness 
or  exact  size. 

Setting-out. — The  setting  out  of  fi*aming  consists  of  marking 
the  Bhoulder  lines  for  the  joints,  and  the  exact  lengths  of  the 
various  members  to  be  fitted  together.  The  nature  of  the  work 
is  so  varied,  and — as  previous  chapters  have  shown — the 
number  of  suitable  joints  for  difierent  purposes  is  so  great, 
that  only  a  few  typical  examples  can  be  illustrated,  although 
the  explanation  given  is  generally  applicable. 

The  setting-out  of  the  work  is  undoubtedly  its  most  important 
side,  and  is  a  test  of  the  efficiency  of  the  craftsman.  He  must 
have  a  thorough  knowledge  of  geometrical  projection  to  be  able 
clearly  to  understand  the  drawings  of  the  architect  or  designer, 
and  a  practical  knowledge  of  detail  to  be  able  to  set  out  all  the 
intricate  framework  with  which  he  may  have  to  deal.  It  may 
happen  that  some  impossible  method  of  construction  is  being 
attempted,  and  it  is  the  business  of  the  craftsman  to  detect  this 
when  setting  out  his  work. 

The  foreman  of  the  workshop  generally  undertakes  the  duty 
of  setting-out,  and  of  solving  any  difficulties  which  may  arise, 
although  he  often  deputes  part  of  this  work  to  the  most  trust- 
worthy of  his  workmen. 

For  the  mass  of  ordinary  panelled  and  sash  framing  it  is 
usual  first  to  draw  out,  to  full  size,  a  horizontal  and  a  vertical 
section  upon  a  rod  or  thin  board  (the  setting-out  rod),  showing 
the  shouldei'  lines,  mortises,  tenons,  and  any  grooving,  rebating 
or  moulding  which  occurs,  and  then  to  transfer  as  many  of  these 
lines  as  are  necessary  to  the  different  members  of  the  frame- 
work.    It  is  impossible  to  give  more  than  a  general  idea  of  how 


WORKSHOP  PRACTICE.  463 

this  is  dune,  since  custom  varies  in  different  workshops,  and  the 
opinions  of  various  craftsmen  differ  as  to  what  is  necessary. 

With  rectangular  framing,  the  sections  supply  all  the  data 
necessary,  but  if  there  are  curved  surfaces,  such  as  circular- 
headed  panels,  curved  heads  to  window  frames,  or  triangular 
spandrel  or  irregular-shaped  framing,  an  elevation  also  is 
needed. 

When  a  number  of  rails  of  the  same  dimensions  and  having 
the  same  thickness  of  tenon  are  cut  with  a  tenoning  machine, 
it  is  only  necessary  to  set  out  one  rail.  This  rail  can  then  be 
used  as  a  template,  and  one  setting  of  adjustable  fences  on  the 
machine,  will  serve  for  the  cutting  of  all  the  remaining  rails. 
A  similar  remark  applies  to  any  tenoning  of  a  number  of 
pieces  (e.g,  muntins)  of  the  same  size,  but  not  to  the  cutting  of 
mortises. 

It  must  be  remembered  that  a  tenon  should  not  have  a  width 
of  more  than  five  times  its  thickness  (p.  170)  and  that  haunched 
tenons  (p.  170)  are  necessary  at  the  corners  of  panelled  framing. 
When  the  edges  of  the  framing  are  grooved,  as  in  nearly  all 
kinds  of  panelled  work,  it  is  necessary  to  allow  for  the  grooves 
since  they  reduce  the  width  of  the  tenons.  When  the 
framing  is  rebated,  as  in  sash  framing  and  the  upper  part  of 
sash  doors,  the  depth  of  the  rebate  has  to  be  allowed  for  in 
marking  the  shoulder  lines.  When  the  inner  arrises  of  the 
sashes  or  other  framework  are  beaded  or  moulded,  this  fact 
must  be  taken  into  consideration  and  allowed  for  in  the  setting 
out  of  the  work. 

The  setting-out  rod  may  be  square  in  section  (about  \\"  side), 
6r  a  thin  board  of  from  7  to  11  inches  wide  may  be  used,  the 
surface  of  which  has  been  covered  with  a  thin  coating  of 
powdered  whitening  mixed  with  very  thin  glue  size,  and  after- 
wards sand-papered  down  until  fairly  smooth. 

Fig.  897  shows  a  rod  upon  which  are  details  for  the  door 
illustrated  in  Fiffs.  674  to  678.  It  will  be  seen  that  from  this 
rod  the  lengths  and  widths  of  all  the  members  of  the  framing, 
the  exact  sizes  of  all  the  panels,  the  lengths  between  the 
shoulder  lines  of  all  rails  and  muntins,  and  the  sizes  of  all 
mortises,  can  be  obtained.  It  is  advisable,  when  transferring 
shoulder  lines  from  the  setting- out  rod  to  such  members  as 
muntins,  to  allow  for  slight  shrinkage  of  the  wide  rails 
during    second    seasoning    (p.    7).      Fig.    898    illustrates    the 


^       i  MANUAI,  OF  CABPENTOY   AOT  «IKEBV. 


WORKSHOP  PEACTICE.  4B& 

ig-out  rod  for  the  pail-  o!  sash  doors  of  Fig  680,  the  upper 

of  which  ai'e  of  glass.  It  is  usual  in 

a  case  to  set  out  one  half  of  the 
ontal  section  to  show  the   lower 

of    the   doors   with  the  panelled 

ag,  and  to  have  upon  the  other  half 
pper  part  which  shows  the  moulded 
s  and  the  rebate  for  the  glass, 
;.  899  shows  a  rod  upon  which  are 
it  atl  the  details  i-equired  for  the 
lent  window  illustrated  in  Figs. 

0  745 ;  and  Fig.  900  shows  a 
ir  rod  with  the  setting-out  lines 
lie  sash  and  fraine  window  given 
avation  and  sections  in  Figs.  770 
i.  It  will  be  noticed  that  on  each 
lese  rods  the  vertical  section  is 
n  on  one  side  and  the  horizontal 
in  upi)n  the  other  side  of  the  rod, 
the  mortises  are  indicated  by  the 
nal  lines,  and  that  an  arrow  head 
Lced  at  each  of  the  shoulder  lines. 
a  wise  precaution  at  all  times  to 
-m,  by  measuring,  the  sizes  of  all 
ngs  in  brick  or  atone  walls  before 
ig  out  the  rods  for  the  window  or 
frames. 

:h  framing  as  movable  panelled 
glazed    partitions,    office    screens, 

framing,  church,  chapel  and 
ibly-rooni  fittings,  and  in  fact 
nds  of  panelled  or  other  framing, 

1  setting  out  by  drawing  upon 
vertical  and  horizontal  sections 
11  size,  and  then  transferring  the 
for  the  shoulders  and  the  mortiseu 
le   material   composing  the  fram- 

With  complicated  framing  the 
ilties  increase  and  nioi'e  care  is 
id,  and  it  will  be  readily   under-     | 

tiat  in  such  li.ard  wood  as  oak,    ' 


466       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

mahogany,   walnut,  tstc,  greater  care  is  needed   in   executi^ 
than  with  the  mass  of  work   done  in  soft  woods. 

The  Putting  Together  of  Framing.— After  the  setting-o- 
conies  the  mortising  and  tenoning,  which  in  hand  work  is  do^ 
before  a.ny  grooving,  rehatin^,  or  moulding.  When  tB 
mortises  and  t«nona  are  machine-out,  they  require  sabseque^ 
examination,  and,  often,  cleaning  up  by  the  workman.  Wh^ 
these  operationa  have  been  completed  it  ia  necessary,  befo  _ 
putting  the  framing  together,  to  sniootli  all  parts  that  canu'^ 
be  smoothed  alterwards.  In  panelled  work  the  panela  mu.  i 
be  inserted  as  the  framing  is  put  together  ;  after  which  3 
is  glued,  cramped  together,  wedged  and  smoothed  off. 


.Mitre  Template. 


When  the  framing  is  solid  moulded,  the  moulded  arrises 
need  to  be  fitted  together  unless  the  mouldings  are  stopped  at 
eath  of  the  joints  as  shown  in  Fig.  658.  The  joint  can  be  made 
by  mitring-  each  of  the  menibe:-s  of  the  framing  as  shown  in 
Fig.  901,  or — which  is  better  because  it  does  not  show  any 
slight  shrinkage  that  may  possibly  take  place — the  members 
may  be  scribed  as  shown  in  Fig,  357.  When  mitring  is 
resorted  to,  a  mitre  template  (Fig.  902)  is  used. 

When  the  mouldings  ai'e  "  planted-in,"  which  is  the  case  with 
the  bulk  of  panelled  framinc;,  a  mitre  blook  (fur  small  mouldings) 
or  a  mitre  l>ox  (for  larger  mouldings)  is  used  in  cutting  the  ends 
of  all  the  mouldings  that  fit  into  I'ectangular  framing.  Figs. 
903  and  904  show  a  mitre  block  and  mitre  box  respectively  ;  it 
will  be  seen  that  each  has  saw  grooves  cut  at  an  angle  of  46°  to 


WORKSHOP  PRACTICE. 


467 


th.^  sides — this  being  the  angle  to  which  the  ends  of  mouldings 
^^ feting  at  a  right  angle  are  cut.  In  nailing  the  mouldings  in 
P^^sition,  care  must  be  taken  to  drive  the  nails  so  that  they 
pierce  the  solid  framing  and  not  the  panel ;    this  leaves  the 


Fio.  903.— Mitre  Block. 


Fio.  904.— Mitre  Box. 


edges  of   the  panel  free  for   slight    shrinkage.      When    the 

singles  of  the  framing  are  not  right  angles,  the  mitre  bisects 

the  angle.     Fig.  905  shows  part  of  a  piece  of  panelled  framing 

suitable  for  the  soffit  of  a  deeply  recessed  shop  doorway,  or 

the  soffit  of  a  bay  window,  in  which  some  of  the  edges  of  the 


I 

'.I 

'I 


•       < 


■\] 


Fio.  905.— Irregular  shaped  Panelled  and  Moulded  Framing. 

framing  are  curved.  When  the  mouldings  of  such  framing  are 
to  be  planted-in,  some  of  the  mouldings  will  be  curved,  and 
the  mitres  of  these  require  special  attention.  In  sorue  cases 
(Fig.  905)  the  mitres  are  curved  surfaces.  The  method  of 
obtaining  the  intersecting  mitre,  when  a  straight  moulding 
meets  a  curved  one  (as  at  A  in  Fig.  905)  or  when  two  curved 
mouldings  intersect  (as  at  B  in  Fig.  905)  is  shown  in  detail  in 
Fig.  906.     The  mitre  line  04  is  an  even  curve  drawn  through 


«S      A  MAN'UAL  OF  CARPENTRY  AND  JOINERY. 

the  pointH  of  intersection  of  the  piit-H  of  equidistant  purailela 
to  AO  and  BO  respectively.  It  will  be  seen  from  Fig.  005  at 
C  that  in  certain  cii'cumstancea  the  interHBction  of  two  curved 
mouldingH,  or  a  curved  and  a  straight  one,  may  be  a  plane  or 
"straight"  mitre. 

Baking  MouldingB  and  Angle  Bars.— In  Chapter  II., 
Figs.  79  and  80  show  methods  of  enlarging  and  diminishing 
mouldinga.  A  modification  of  this  geometrical  principle  is  Co 
be  found  when  a  moulding,  fixed  against  a  vertical  wall  in  m 
inclined  (raking)  position,  intersects  a  horizontal  moulding 
against  a  wall  at  right  angles  to  the  first  one.     Fig.  907  shows 


Fio.  toe.— Bntargcd  dc 


bow  to  obtain  the  shape  of  the  horizontal  moulding  on  the 
upper  edge  of  a  skirting  board  which  has  to  mitre  into  the 
inclined  skirting  board  of  the  given  cross  section.  To  obtain  a 
true  intersection  at  the  angle,  the  horizontal  moulding  is 
necessarily  of  difterent  shape  from  the  raking  moulding.  Fig. 
008  shows  another  type  of  laking  moulding  with  the  shapes  of 
horizontal  wturns  at  both  the  upper  and  the  lower  ends.  The 
:'eturn  in  each  case  is  upon  a  vertical  surface  and  through  a 
right  angle.  The  projection  of  the  various  members  beyond 
the  face  of  the  wall  is  the  same  in  each  case,  as  indicated  by  the 
corresponding  numbers  Fig.  009  shows  the  method  of  obtain- 
ing the  shape  of  a  moulded  angle-bar  for  a  shop  window  or 
some  similar  framing. 


WORKSHOP  PRACTICE. 


470      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

Angle  Brackets. — The  ceilings  of  rooms  are  often  relieved 
by  having  plaster  cornice-moulds  run  in  the  angle  between  the 
ceiling  and  the  vertical  walls.  When  the  cornice  is  large,  the 
plasterers'  laths  supporting  it  are  carried  by   rough   wooden 


Fio.  911.— Plan  of  an  Irregula-^ 
Shaped  Room. 


Fio.  910. — Methods  of  obtaining  shajxss  of  Angle 
Brackets  in  Fig.  Oil. 


brackets  (angle  brackets)  placed  about  15  inches  apart  along  the 
intersection  of  the  wall  and  the  ceiling.  These  brackets  are  cut 
approximately  to  the  shape  of  the  section  of  the  cornice  as 
shown  in  Fig.  910.  Specially  shaped  brackets  are  needed  for 
the  support  of  the  ends  of  the  laths  at  the  corners  of  the  room. 


WORKSHOP  PRACTICE.  471 

The  method  of  determining  the  shape  of  such  comer  brackets 
is  an  excellent  example  of  geometrical  projection,  and  is  shown 
in  detail  in  Fig.  910.  Fig.  911  shows  the  i)lan  of  a  peculiarly 
shaped  room,  purposely  selected  to  give  variety  of  corners.  The 
reference  letters  of  Figs.  910  and  911  are  identical,  and  Fig.  910 
shows  the  outline  of  the  corner  brackets  at  A,  B,  and  C.  In 
cutting  out  these  corner  brackets  it  is  necessary  first  to  prepare 
a  template  of  the  required  shape.  The  template  is  then 
applied  to  the  surface  of  the  material,  and — as  the  edges  of 
the  corner  brackets  are  not  at  right  angles  to  their  vertical 
plane,  but  must  be  cut  so  that  they  are  in  line  with  the  other 
brackets  as  shown  in  Fig.  911 — the  bevels  to  which  the  edges 
are  cut  must  be  obtained  from  the  plan  of  the  room.  The 
template  must  be  applied  to  both  sides  of  the  material  to 


Fio.  912. — Method  uf  fiuding  tbo  distances  apart  of  the  SaW'Korfs 

when  bending  boards. 

correspond  to  the  edge  bevel  required.  A  similar  construction 
is  applicable  wherever  large  wooden  moulded  cornices  meet  at 
an  angle  and  have  to  be  supported  by  wooden  brackets. 

Saw-Kerfing. — Curved  surfaces  are  often  "cut  out  of  the 
solid "  and  dressed  to  the  required  curvature.  It  is  occasion- 
ally necessary,  however,  to  bend  a  board  to  obtain  a  curved 
surface.  In  addition  to  the  methods  already  explained  of  bend- 
ing boards  (pp.  401  and  440),  a  method  often  adopted  is  to  make 
saw-cuts  (kerft)  in  the  side  which  is  to  be  concave,  at  such  dis- 
tances apart  that  in  order  to  close  the  kerfs  the  board  must  be 
bent  to  the  required  curvature. 

A  ready  appliance  for  obtaining  the  exact  distances  apart  of 
the  saw-kerfs  ia  illustrated  in  Fig.  912.  It  consists  of  a  lath  of 
exactly  the  same  thickness  as  the  board  to  be  bent.  About  the 
middle  of  the  lenf^th  of  this  lath  a  saw-kerf  is  made.  The  lath 
is  then  bent  until  the  kerf  closes,  and  the  angle  through  which 


472      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

it  hiLs  been  turned  ft'uiii  the  atmight  line  is  obtained.  An  arc 
of  a  circla  is  then  struck  {Fig.  912)  with  A  ab  centre  and  a, 
mdtua  equal  to  the  radius  of  the  curve  required.  The  chord 
BB  of  the  arc  is  the  distance  apai't  of  the  kerfs  to  be  cut  in 
the  board  to  be  bent.  Similarly,  with  a  curve  of  radius  AC, 
CC  gives  the  distance  apart  of  the  saw-kerfs ;  and,  again,  BD 
would  be  the  distance  apart  of  kerfa  required  for  curvature  of 


Horizontal  Secrion. 

itliod  of  i> 


(1)  The  lath  muat  be  of  exactly 

the  same  thirkiies. 

as  the 

boai'd  to  be  1>cnt 

(2)  AH  tlR  ■««  keif*  must  lie  i 

uiio  with  the  siiiie 

B-iw,  i.e. 

the  saw  used  foi  tutting  the  1  ith 

(3)  The  depths  of  all  tlit    \tif- 

must    be  o,ua    t 

t\   deep 

enough  to  allow  of  bending  witho  i 

.  bieaking  the  filne 

s  on  the 

convex  side  of  tlif  board 

Splayed  Linings.— Fig.  913  shn 

ws  the  uppei    pait 

of   the 

WORKSHOP  PRACTICE. 


473 


elevation,  a,  honKontal  sei^tion,  and  a  vettical  sectioo  of  the 
inside  linings  of  a  window  or  door  frame,  where  both  the  jamb 
and  head  liningH  are  "splayed."  To  obtain  the  lines  of  inter- 
section of  the  oblique  (splayed)  planes,  it  is  necessary  to  draw 
out  the  appearance  of  each  when  the  two  have  been  rotited  into 
the  same  plane.  In  Fig.  913  ab  is  the  horizontal  eectiou  and 
a'a',  b'h'  the  elevation  of  the  front  face  of  the  jamb-lining  on  the 
right-hand  aide.  The  line  ab  is  rotated  on  «  as  centre,  and  the 
true  shape  of  the  front  face  thus  developed  is  seen  to  be  c'a' 
BB  ;  while  angle  1  gives  the  bevel  for  the  side  cut.  Similarly, 
by  rotating  the  line  cd  on  centre  c,  the  development  Dn'c'D  of 


the  head  is  obtained  :  the  bevel  of  the  head  at  its  intersection 
with  the  janib  being  given  by  the  angle  2. 

The  method  of  obtaining  the  angle  (marked  3)  which  the  edge 
cut  makes  with  the  face  of  the  jamb-lining  is  shown  on  the 
left-hand  side  of  the  drawing.  As  a,  geometrical  problem  it  is 
the  deternii nation  of  the  angle  between  two  planes,  i.e.  the  faces 
of  the  vertical  jamb-lining  and  the  head-lining,  m'n'  is  the 
elevation  of  the  line  of  intersection  of  these  two  planes,  and 
Mn'  shows  its  true  length,  because  Mm'  is  equal  to  uk  in  the 
horizontal  section.  Through  M  draw  MO  parallel  to  m'n'.  From 
any  point  0  in  MO  draw  Ox  perpendicular  to  Mn',  and  through 
0  draw  yj  pei'pendicular  to  m'n'.  Make  Ox'  equal  to  Ox  and 
draw  ,V;e' perpendicular  to  m'n'.    Join  Xy  and  A'z.    The  angle 


474      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

yXz  is  the  angle  between  the  two  planes,  and  its  complement 
3  is  the  angle  of  the  edge  cut. 

The  principles  involved  in  this  exercise  are  applicable  also  to 
the  construction  of  hoppers,  triangular  louvre  ventilators,  and 
to  splayed  work  generally. 

Fig.  914  shows  splayed  linings  for  an  opening  with  a  semi- 
circular head.  Fig.  915  shows  the  development  of  the  circular 
part,  which  is  a  portion  of  the  stretch-out  of  a  cone.  The 
numbering  indicates  corresponding  points  on  the  two  drawings. 

Circle-on-Circle  Work. — Circle-on-circle  work,  as  the  name 
implies,  involves  the  construction  of  framing  which  is  circular  in 


•A 

Fio.  915.— Dovolopment  of  the  curved  part  of  the  Splayed  Lining-  in 

Fig.  914. 

both  plan  and  elevation.  It  generally  occurs  in  door  or  window 
frames  which  are  segmental  in  plan,  and  have  the  upper  part 
(head)  semicircular  in  elevation.  Fig.  916  is  an  illustration  of  a 
typical  example  with  "  radiating "  jambs.  The  curved  part  of 
such  frames  is  usually  built  up  of  two,  three,  or  more  members, 
according  to  size.  As  the  curved  membeis  are  of  necessity 
worked  out  of  rectangular  pieces,  and  have  the  joints  prepared 
before  the  curved  surfaces  are  worked,  the  determination  of  the 
minimum  size  of  material  required,  and  of  the  bevels  to  which 
the  ends  must  be  cut,  needs  careful  consideration.  In  Fig.  916 
the  minimum  thickness  of  the  material  is  the  perpendicular 
distance  between  MN  and  P§.  The  face  joints  are  shown  at 
X  and  F,  the  point  x  being  obtained  by  drawing  through  o 
perpendicular  to  VQ.     The  edge  joint  at  the  lower  end  is  per- 


WORKSHOP  PRACTICE. 


ir  marking  out  the  curvatui-e  of  the  upper  and  lower  faces. 
hey  are  obtained  by  developing  the  vertical  plane  PQ  for  the 


476     A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

outer  (coDvex)  side,  and  the  vertical  plane  UN  for  the  inow 
(coucave)  side.  The  deyelopment  is  io  each  case  an  even  cum 
drawn  thruugh  points  obtained   by  meaaurin)^,  from  PQ  uid 


I'lu.  !J1T.— Uuiiii>.pliurl<:Hl  rutidcTiIlvo  Cradling. 

MX  respeetivel)-,  ordinates  equal  in  lengtli  to  correspond  ing 
oiiJinates  projected  from  the  elevation.  After  working  these 
curved  surfaces,  the  lines  to  which  to  cut  the  vertical  curved 
surfaces  are  obtained  by  transferring  the  hoiizontal  radiating 
lines  11,  2  S,  3  3,  etc.,  to  the  upper  and  lower  surfaces,  and 


WORKSHOP  PRACTICE.  477 

measuring  along  these  lines  the  points  cc,  dd,  ee^  etc.,  from  the 
faces  PQ  and  MN  respectively.  Even  curves  drawn  through 
these  points  give  the  lines  required.  Any  rebating  or  moulding 
of  the  an'ises  may  be  done  easily  by  working  parallel  to  the 
curved  surfaces.  Joints  in  circle-on-circle  work  usually  abut 
normally  to  the  curve,  and  are  secured  with  hammer-headed 
"keys  (Fig.  368)  or  handrail  bolts  (Fig.  892)  and  dowels. 

Pendentives. — When  a  room  is  lighted  from  the  ceiling,  as  in 

art  galleries,  museums,  etc.,  the  ceiling  of  the  room  often  takes 

the  shape  of  a  dome.   With  such  a  construction  the  wooden  curb 

(p.  420)  which  carries  the  roof -light  is  supported,  as  is  also  the 

plastered  ceiling,  by  rough  wooden  brackets  or  cradling.     Such 

a  treatment  is  said  to  be  pendentive,  and  the  rough  wooden 

framework  is  known  as  pendentiye  cradling.    The  ceiling  may 

have  either  circular  or  elliptical  curved  ribs,  and  the  curb  upon 

which    the    lantern    light    rests    may   be    square,    polygonal, 

circular,  or  elliptical.     If  the  curved  ribs  are  long,  they  may  be 

built  up  of  two  or  three  thicknesses    nailed  together  with 

overlapping  joints.     Fig.  917  shows  the  details  of  the  pendentive 

cradling  for  a  ceiling  the  shape  of  which  is  hemispherical ;  it 

supports  a  circular  curb. 


FIXING  OF  JOINERS'  WORK. 

If  the  finished  wrought  woodwork  is,  after  being  properly 
seasoned,  fixed  in  position  in  a  new  building  before  the  walls 
and  the  plaster  are  dry,  it  will  absorb  moisture  and  swell, 
and,  after  drying,  it  will  be  apparent  that  the  joints  have  been 
strained.  On  this  account,  therefore,  all  finished  work  should, 
as  far  as  possible,  be  left  unfixed  until  the  building  is  quite 
dry.  The  method  of  fixing  depends  upon  the  class  of  building 
and  the  character  of  the  finished  work.  The  usual  plan  is  to 
fix  wooden  battens  called  grounds  to  the  walls  around  all 
doorways,  window  openings,  and  along  the  walls  for  the  upper 
edges  of  skirting  boards,  dado  framing,  and  in  fact  generally 
where  finished  woodwork  has  to  be  secured  to  the  wall.  These 
grounds  are  nailed  either  to  slips  which  have  been  built  into 
the  wall,  or  to  plugs  driven  into  the  joints  between  the  bricks. 
The  grounds  around  doorways  and  window  openings  are  framed 
at  the  angles,  and   it  is   necessary   to  arrange  that    all    the 


478      A  MANUAL  OF  CARPENTRY  AND  JOINERY.  ' 

grounds  nn  the  same  wall  shall  be  in  the  some  vertical  plane,  ^ 
that,  as  the  plasterer-  uses  them  for  a  guide  when  plaaterii*8 
the  surface,  he  will  be  able  to  obtain  true  surfaces.     Ir*^" 


undfl,  Anglo  Boada,  Qto. 

holdfasts  are  sometimes  used  for  securing  such  grounds, 
especially  around  chimney  flues.  Fig.  918  shows  how  tha 
grounds  are  fixed  in  part  of  a  doorway,  and  also  behind  tha 
skirting  boards.  In  the  mass  of 
ordinary  work  the  finished  material 
is  nailed  or  screwed  to  the  grounds, 
with  the  nails  punched  below  the 
sui:face  and  the  nail-boles  afterwards 
puttied- up  by  the  painter.  In 
superior  work,  where  such  material 
as  oak,  mahogany,  etc.,  is  used, 
and  where  the  finished  surface  is 
after  wai-ds  polished,  any  visible 
nail-holes  OP  screws  would  be  objec- 
tionable, secret  screwing  is  largely 
resorted  to.  In  addition  to  this, 
the  material  is  so  constructed  that 
t«ngued  and  grooved  joints  and  glue  blocks  are  largely  used 
as  fastenings.  Fig.  919  illustrates  a  method  which  may 
occasionally  be  used  with  advantage.  It  consists  of  cutting 
a  narrow  chase  of  small  depth  into  the  face  of  the  boai'd, 
I'aising  carefully  the  part  cut,  driving  a  nail  or  a  screw  into 


It  Nsiling. 


FIXING  OF  JOINERS'  WORK.  47tf 

,  nnd  then  gluing  the  raised  portion  into  its  original 


Figs.  920,  921,  and  922  are  sections  through  three  differeot 
fomiB  of  skirting  boards,  with  their  names  attached.      In  the 
vJ^st    class    of    work    the    lower   edge    of    the 
skirting  is  tongued  into  the  floor.  M^V^<^^^ 

Angle    Beads.— When    an    enternal    angle     H>^x;?^s5i 
Occurs   in   a   i-oom,   as   at    X   in    Fig.  918,  an 
angle  or  staff  bead  is  fixed  by  means  of  wooden 
plugs  to  the  wall  as  a  guide  foi'  the  plasterer, 
as  well  as  to  protect  the  angle.    Fig.  923  is  a     I     ""Plaster 
horizontal  section  of  an  angle  bead.     The  bead     Anglebead. 
is  sometimes  dispensed  with,  and  the  plasterer         Fio.  923. 
works  the  angle  in  cement. 


480       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


Summary. 

A  workshop  should  have  abundance  of  light,  be  properly  heated 
in  winter,  and  have  special  regard  paid  to  the  arrangement  of  the 
benches,  machinery,  storage  arrangement,  artificial  lighting,  etc. 

In  the  preparation  of  framing  by  liand  labour,  both  the  **  trueing- 
up  "  of  the  material,  and  the  systematic  testing  for  straightness  and 
size  call  for  great  care. 

The  ability  to  "  set  out "  all  kinds  of  wooden  framing  is  one  of  the 
surest  tests  of  the  skill  of  the  craftsman.  The  setting  out  is  usually 
first  done  on  rods,  the  measurements  being  afterwards  transferred 
from  these  rods  to  the  various  members  of  the  framing. 

Panelled  framing  may  have  the  mouldings  worked  on  the  arrises, 
or  they  may  be  "planted  in."  The  mitre  block  or  mitre  box  is 
often  used  for  mouldings  which  are  mitred.  In  certain  ciises  the 
mitre  of  two  intersecting  mouldings  is  a  curved  surface. 

When  a  rakin^^  moulding:  intersects  a  horizontal  moulding  at  an 
angle  between  two  planes,  the  two  mouldings  are  of  different  shape. 

A  board  can  be  bent  to  almost  any  radius  by  cutting  equi- 
distant saw-kerfs  on  one  face.  The  distance  apart  of  the  kerfs 
depends  upon  (1)  the  radius  of  curvature;  (2)  the  thickness  of  the 
l)oard  to  be  bent ;  and  (3)  the  thickness  of  the  saw  used. 

In  splayed  linings,  circle-on-circle  work,  and  pendentive  cradling:, 
the  practical  application  of  geometrical  principles  of  projection  is 
necessary  for  the  determination  of  the  sizes  of  the  material,  and  the 
bevels  of  the  joints. 

Finished  woodwork  is  fixed  to  grounds  plugged  to  the  walls  of 
the  building.  It  should  never  be  taken  to  the  building  until  the 
walls  and  the  plaster  are  dry. 


Questions  on  Chapter  XVII. 

1.  Show  how  you  would  set  out  on  a  rod  for  an  inside  four- 
panelled  door  and  frame.     Size  of  door  7  ft.  by  3  ft.  by  2  in. 

2.  Show  how  you  would  set  out  a  rod  for  a  window-frame  fitted 
with  a  pair  of  French  casements.     (C.  and  G.  Hon.,  1898.) 

3.  Make  a  drawing  of  a  piece  of  irregular-shaped  panelled  and 
moulded  framing,  some  of  tlie  panels  of  which  have  curved  edges, 
and  determine  the  shapes  of  all  the  mitres  of  the  mouldings, 
assuming  tliem  to  be  planted  in. 

4.  (a)  Give  an  illustration  of  the  method  of  diminishing  the 
section  of  a  moulding,     {h)  Show  how  you  find  the  section  of  a 


QUESTIONS  ON  CHAPTER  XVII.  481 

raking  moulding,  suoh  as  is  used  in   the  angle  of  a  shop  front. 
(C.  andG.  Ord.,  1899.) 

5.  Show  how  you  would  determine  the  section  of  an  angle  bar  of 
a  shop  front,  also  how  the  bar  is  connected  to  the  top  and  bottom 
rails  and  how  the  rails  are  joined  at  the  angles.  (C.  and  G.  Ord. , 
1904.) 

6.  Show  and  explain  fully  the  method  of  obtaining  the  moulds 
for  angle  brackets  for  finishing  the  moulded  bottom  of  an  oriel  bay 
window,  half  octagon  on  plan.     (C.  and  G.  Ord.,  1895.) 

7.  It  is  required  to  run  a  bracketed  plaster  cornice  (24  inches 
girth)  round  a  room,  one  angle  of  which  is  75  degrees  on  plan. 
Give  a  plan  and  section  (1  inch  scale  to  the  foot)  of  the  cornice, 
showing  the  brackets  and  also  an  elevation  of  the  angle  bracket. 
(C.  andG.  Ord.,  1892.) 

8.  Describe  some  different  methods  of  bending  wood  for  circular 
work  other  than  steaming,  also  some  ways  of  joining  desk  framing 
at  angles.     (C.  and  G.  Ord.,  1895.) 

9.  The  inside  linings  of  a  window  opening  are  9  in.  wide,  and  are 
(including  the  head)  splayed  to  the  extent  of  3  in.  Determine  the 
bevels  to  which  the  upper  ends  of  the  jambs  must  be  cut. 

10.  Explain  fully  how  you  would  get  out  and  put  together  the 
hesud  of  a  sash,  circular  on  plan  and  segmental  in  elevation. 
(C.  andG.  Hon.,  1894.) 

11.  Describe  the  method  of  framing  up  a  sash  circular  on  plan 
and  in  elevation,  showing,  by  drawing,  the  lines  for  getting  out  the 
moulds,  etc.     (C.  and  G.  Hon.,  1893.) 

12.  Show  the  method  for  obtaining  the  face  mould  of  a  solid  door 
frame  head  **circle-on-circle."    (C.  and  G.  Hon.,  1899.) 

13.  A  square  lantern  light,  6  feet  internally,  has  in  the  centre  an 
opening  1  foot  6  inches  in  diameter,  octagonal  on  plan.  The  hips 
are  moulded  to  the  same  section  as  the  mouldings  round  the 
opening.  Show  by  scale  sketches  how  you  would  obtain  the  inter- 
section of  the  mouldings.     (C.  and  G.  Hon.,  1892.) 

14.  Make  a  drawing  of  sufficient  of  the  plan  and  elevation  of  an 
octagonal  dome  8  ft.  in  diameter  Ixmrded  internally.  All  the 
applied  geometry  should  be  clearly  shown  in  the  drawings.  (C.  and 
G.  Hon.,  1900.) 

15.  Draw  the  construction  of  a  small  hemispherical  dome  12  ft.  in 
diameter,  to  Ix)  formed  in  the  flat  roof  of  a  billiard  room  measuring 
20  ft.  by  30  ft.  Show  the  necessary  trimming  for  supporting  the 
dome,  and  the  timber,  etc.,  of  the  dome  itself.     (C.  and  G.  Hon., 

1900.) 

M.C.J.  2  H 


482       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

16.  Draw  to  ^  inoh  scale,  section  through  a  room  panelled  in 
wood,  with  4  full  size  details  of  cornice,  chair  rail  and  skirting. 
Height  of  room  12  ft.     (C.  and  G.  Hon.,  1896.) 

17.  A  room,  20  ft.  by  15  ft.  has  a  bay  window,  fireplace,  and  two 
doorways.  Describe  the  method  of  fixing  the  grounds  to  receive 
the  skirtings,  architraves,  etc.     (C.  and  G.  Ord.,  1898.) 


*v 


CITY  AND  GUILDS  OF  LONDON  INSTITUTE, 


DEPARTMENT  OF  TECHNOLOGY. 


TECHNOLOGICAL  EXAMINATIONS,    1905. 

CARPENTRY  AND  JOINERY. 
Preliminary  Examination. 

Instructions. 

Candidates  may  take  the  Ordinary  Grade  without  having  passed 
the  Preliminary  Examination  ;  or  both  Examinations  may  be  taken 
in  the  same  year. 

A  sheet  of  drawing  paper  is  supplied  to  each  Candidate. 

Three  Jumrs  are  allowed  for  this  paper. 

Not  more  than  ten  questions  to  he  attempted. 


1.  A  metre =39-37079  ins.  What 
is  the  area,  in  metres,  of  a  room  31  ft. 
6  ins.  by  12  ft.  6. ins.  ?    (30  marks.) 

2.  Divide  a  line  4J  ins.  long  into 
tenths,  and  subdivide  one  such  part 
into  sixths ;  dividers  not  to  be  used. 
(25.) 

3.  Make  an  oblong  equal  in  area  to 
the  given  figure.     (30. ) 


484       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

4.  The  side  of  a  circular  tank,  7  ft.  6  ins.  diameter  and  3  ft.  9  ins. 
high,  has  to  be  covered  externally  with  matchboard.  How  many 
square  feet  are  required  ?    (35. ) 

5.  Calculate  the  superficial  area  of  the  wall  surface  shown  upon 
the  diagram.     (30.) 


I 

I 
I 


A 

1 
1 

r  A 

1 

&  1 

O 

^6 

<-2  9* 

A 

1 

1 
1 

/    It 

1 

CD 
O 

1 

1 

^ 

160   -- 


6.  The  dimensioned  sketch  shows  plan  and  section  of  a  roof ;  it 
has  to  be  boarded.  What  will  be  the  superficial  area  of  boarding 
required?    (30.) 


-200  - 


7.  A  piece  of  timber  is  20  ins.  square  at  one  end  and  11  ins. 
square  at  the  other,  its  length  is  16  ft.  6  ins.,  weight  74  lbs.  per 
cubic  foot.     Find  the  cubic  contents  and  the  weight.     (40. ) 

8.  A  window  is  4  ft.  3  ins.  wide  ;  it  has  an  elliptic  arch  rising 
10  ins.  from  the  springing  line.  Make  a  drawing  of  the  centre  for 
the  arch.     (25. ) 

9.  Draw  the  plan  and  elevation  of  a  cylinder  3  ins.  diameter, 
4  ins.  axis,  standing  on  one  end.  The  axis  is  cut  by  a  plane  inclined 
at  60"  to  the  axis.     Draw  the  section.     (35.) 


TECHNOLOGICAL  EXAMINATIONS,  1905.  485 

10.  Represent  in  isometric  or  oblique  projection  the  following 
joints,  and  dimension  the  parts  : 

(1)  Haunohed  mortise  and  tenon. 

(2)  Groove  and  tongue  for  skirting. 

(3)  Tusk  tenon  joint. 

(4)  Mitre  bridle  joint.     (30.) 

11.  Make  the  drawings  of  a  solid  door  frame,  rebated  and  beaded, 
to  receive  a  2- in.  door  3  ft.  wide,  6  ft.  3  ins.  high.     (35.) 

12.  A  cubic  foot  of  timber  floating  in  water  is  submerged  to  a 
depth  of  9J  inches.  What  is  its  specific  gravity?  What  weight 
placed  on  the  top  of  the  timber  will  suffice  to  just  submerge  it? 
(40.) 

13.  A  beam  25  ft.  long,  weighing  15  cwt.,  is  supported  on  two 
walls  ;  it  carries  a  load  of  6  cwt.  12  ft.  from  one  end,  and  2  cwt.  4  ft. 
from  the  other  end.     Find  the  pressures  on  the  two  walls.     (40.) 

14.  Give  a  short  description  of  the  undermentioned  saws,  and  the 
reason  for  the  various  shapes  of  the  teeth  : 

Dovetail  saw. 
Tenon        ,, 
Hand         ,, 
Rip  ,, 

Bow  „     (25.) 

15.  Give  a  short  description  of  the  following  timbers,  and  the 
uses  to  which  they  may  be  put :  Mahogany,  pitch  pine,  yellow  deal. 
Also  state  the  countries  from  which  they  are  obtained.     (25. ) 

16.  Make  a  drawing  of  a  collar  beam  roof,  16-ft.  span. 

Or, 
Make  a  drawing  of  a  dwarf  cupboard  front.     (30. ) 


Instructions. 

The  Candidate  must  confine  himself  to  one  grade  only,  the 
Ordinary  or  Honours,  and  must  state  at  the  top  of  his  paper  of 
answers  which  grade  he  has  selected.  He  must  Tiot  answer  questions 
in  more  than  one  grade. 

K  he  has  already  passed  in  this  subject,  in  the  first  class  of  the 
Ordinary  Grade,  he  must  select  his  questions  from  those  of  the 
Honours  Grade. 

A  sheet  of  drawing  paper  is  supplied  to  each  Candidate. 

Drawing  instruments  to  be  used  in  this  Examination. 

Four  hours  allowed  for  this  paper. 


486       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

Ordinary  Grade. 

Not  more  than  ten  qtieationa  to  he  attempted. 

1.  (a)  Make   sketches  to  show  how  oak  logs  are  converted   to 

obtain   (1)   timber  of  the  maximum   strength,    and  (2) 
boards  for  joiners'  work. 

(6)  What  is  water  seasoning?    How  does  it  affect  timber  as 
compared  with  other  forms  of  seasoning  ?    (25  m^rks. ) 

2.  Some  planes  are  fitted  with  pairs  of  irons,  others  with  single 
irons.    Why  is  this?    Give  sketches  to  illustrate  your  answer.     (25.) 

3.  Make  the  elevation,  vertical  and  horizontal  section  of  a  2-in. 
sash  door,  3  ft.  3  ins.  wide,  and  6  ft.  9  ins.  high,  the  bottom  panels 
to  be  moulded.  All  construction  to  be  shown  by  dotted  lines,  and 
the  drawings  to  be  fully  dimensioned.     Scale,  1  in.  to  ft.     (40. ) 

4.  What  would  be  the  sectional  area  of  an  oak  beam  to  carry  a 
distributed  load  of  6  tons  on  a  span  of  10  ft.  ?    (35. ) 

5.  Make  a  plan  to  J -in.  scale  of  an  open  newel  staircase  to  fit 
the  space  shown ;  the  height  from  floor  to  floor  is  10  ft.  3  ins. 
Going  to  be  10  ins.,  rise  not  more  than  6 J  ins.,  no  winders. 
Number  steps,  and  show  all  bearers  and  carriages.  Make  a  sec- 
tion I  full  size  of  one  tread  and  riser,  showing  framing  and 
housing  into  string.     (50.) 


i 


o 
ob 


I 


3 


I 


d 

"CO 

I 

if 


I 

m 


Up 


7-6 > 


6.  Make  drawing  to  show  how  a  fireplace  in  a  single  floor  would 
be  trimmed  round.     Scale,  1^  ins.  to  1  ft.     (25.) 

7.  Make  sketches  of  the  following  joints  :  Secret  dovetail,  mor- 
tise and  tenon  for  the  lockrail  of  a  door,  two  forms  of  scarfing  joints, 
the  meeting  styles  of  French  casements.     (30. ) 

8.  The  sketch  shows  a  hrick  arch  in  elevation  and  section  ;  make 
to  a  scale  of  1  in.   to  1  ft.  an  elevation  and  cross  section  of  the 


TECHNOLOGICAL  EXAMINATIONS,   1905. 


487 


necessary  centre  for  its  construction.  How  would  you  fix  and 
strike  the  centre  ?  The  springing  of  the  arch  is  assumed  to  be  10  ft. 
from  the  ground.     (35. ) 


-^—1—0- 


<  -  -12-0 


_  _\ 


I 
I 


9.  Make  a  drawing,  showing  rather  more  than  half  elevation,  and 
vertical  section  of  a  solid  door  frame,  with  transom  beaded  on  one 
edge,  rebated  and  beaded  on  the  other,  to  receive  a  2in.  door  and  a 
fanlight  over  door.  Also  make  a  sketch  to  show  the  joint  at  the 
head  of  the  frame  ;  width  of  opening,  3  ft.  2  ins. ;  height,  9  ft.    (30. ) 

10.  Make  detail  drawings  of  a  "box  gutter"  9  ins.  wide,  and 
**  cesspool"  6  ins.  deep,  showing  how  the  work  is  prepared  for  the 
plumber.  State  what  fall  the  gutter  should  be  given,  and  how  far 
apart  the  drips  should  be.     (40. ) 

11.  Draw  rather  more  than  half  elevation  of  a  framed  and  trussed 
partition,  18  ft.  wide,  11  ft.  6  ins.  high ;  the  partition  to  have  an 
opening  in  the  centre  for  a  pair  of  folding  doors  7  ft.  wide  and 
7  ft.  3  ins.  in  height.  The  partition  has  to  carry  its  own  weight 
and  that  of  the  floor  above.  Fully  dimension  the  scantlings  used. 
Scale,  J  in.  to  1  ft.     (40.) 

12.  The  roof  of  an  attic  storey  has  a  slope  of  60  degrees,  and  the 
storey  is  9  ft.  high  in  the  clear.  The  sill  of  a  dormer  window  is 
3  ft.  6  ins.  above  the  floor  ;  the  window  is  3  ft.  wide,  and  as  high  as 
possible.  Make  elevation  and  section,  or  an  isometric  sketch,  to  a 
scale  of  ^  in.  to  a  foot,  showing  the  framing  required  to  form  the 
window,  including  cheeks  and  roof  and  all  trimming.  No  joinery 
need  be  shown.     (35. ) 

13.  A  solid  window-frame,  3  ft.  6  ins.  wide  and  2  ft.  3  ins.  high, 
is  fitted  with  a  pair  of  2  in.  sashes  hung  with  butts  to  open  exter- 
nally. Make  vertical  and  horizontal  sections,  showing  how  the  wet 
would  be  kept  out.     Choose  your  own  scale.     (30. ) 


488       A  MANUAL  OF  CARt>ENTRY  AND  JomEllY. 

14.  A  roof  has  a  span  of  42  ft.  Make  a  drawing  of  rather  more 
than  half  elevation  of  the  truss.  Fully  dimension  the  scantlings 
used.  Scale,  ^  in.  to  1  ft.  Also  make  sketches  of  the  joints  of  the 
truss,  about  J  full  size.     (40. ) 

15.  A  framed  dado  is  2  ft.  9  ins.  high.  Make  drawing  of  the 
frame  showing  the  construction  and  fixing,  and  how  the  external 
and  internal  angles  would  be  secured.     Scale,  1^  ins.  to  1  ft.     (40.) 


Honours  Grade. 

Written  Examination. 

Candidates  for  Honours  miiftt  have  previously  passed  in  the 
Ordinary  Grade,  and  must  have  already  forwarded  to  the  Institute 
a  specimen  of  their  Practical  Work.  They  are  also  required  to  attend 
an  approved  centre  for  a  Practical  Test. 

Not  more  than  ten  questions  to  he  attempted. 

1.  Make  half  elevation,  and  vertical  and  horizontal  sections  of  a 
circular-headed  cased  sash-frame,  fitted  with  2-in.  double-hung 
sashes.  Show  two  methods  of  constructing  the  head  of  frame. 
(35  marks. ) 

2.  Make  a  plan  of  the  timbers  of  a  double-framed  floor  for  the 
room  shown,  to  a  scale  of  |  inch  to  1  ft.  Girders  to  be  10  ft.  apart, 
and  14  ins.  by  10  ins. ;  binders,  10  ins.  by  7  ins.  Show  all  other 
timbers  and  figure  sizes.  Give  section  of  girder  J  full  size,  showing 
framing  of  binders  and  bridging  and  ceiling  joists.     (35. ) 


Lift 


3.   Make  half  elevation,  a  vertical  and  horizontal  section  of  a 
window  fitted  with  a  pair  of  French  casements  with  fanlight  over. 


TECHNOLOGICAL  EXAMINATIONS,   1905. 


48d 


Width  of  opening,  4  ft.  6  ins.  ;  height,  9  ft.  6  ins.     Scale,  1  in.  to 
1  ft.     (30. ) 

4.  A  shop  front,  14  ft.  long,  exclusive  of  any  door,  is  to  be 
arranged  so  as  to  light  a  basement  storey  by  means  of  a  glazed  stall 
board  3  ft.  high  from  pavement.  The  shop  floor  is  6  ins.  above 
pavement,  and  10  ins.  thick.  Make  a  section  through  stall  board 
and  sill  of  front,  showing  bulkhead  in  shop,  and  give  elevation  of 
bulkhead  from  shop,  one  half  to  show  framing,  the  other  half  the 
finishing.     Scale,  ^  in.  to  1  ft.     (45. ) 

5.  Make  drawing  sufficient  to  show  the  construction  of  a  pair  of 
swing  doors  and  frame,  such  as  are  used  in  first-class  office  fittings. 
Scale,  1  in.  to  1  ft.     (35. ) 

6.  A  geometrical  staircase  has  a  veneered  string.  Show  how  the 
development  of  the  string  is  obtained.  Take  any  size  of  well-hole 
you  please.     (30. ) 

7.  Make  an  elevation,  showing  the  framing  of  one  of  a  pair  of 
yard  gates  for  an  opening  12  ft.  wide.  Each  gate  to  be  7  ft.  6  ins. 
high  at  meeting  style,  9  ft.  at  hanging  style,  and  to  be  hung  with 
strap  hinges,  and  to  have  a  moulded  capping.  The  gate  shown  to 
have  a  wicket  door,  not  less  than  2  ft.  3  ins.  by  5  ft.  6  ins. ,  formed 
in  it.     Scale,  1  in.  to  1  ft.     (35. ) 

8.  A  stepped  gallery  extends  across  one  end  of  a  church  50  ft. 
wide  ;  the  front  of  the  gallery  is  fixed  at  each  end  to  the  external 
walls,  and  carried  by  two  columns,  each  12  ft.  from  the  wall. 
Draw  a  cross-section  through  the  gallery  ;  make  provision  for  four 
rows  of  pews.     The  pews  need  not  be  shown.     (35. ) 

9.  Draw  a  section  and  an 
elevation  of  a  portion  of  the 
gallery  front  in  the  foregoing 
question  sufficient  to  show  the 
construction.  The  front  has  to 
provide  a  book-rest.     (30. ) 

10.  The  sketch  indicates  the 
front  of  a  detached  house,  with- 
out a  basement ;  it  is  proposed 
to  take  out  the  whole  of  the 
ground-floor  wall,  and  to  insert 
a  girder  on  piers  or  stanchions 
with  a  view  to  forming  a  shop. 
Make  an  elevation  and  section  to 
J  in.  scale.     Show  the  positions 


490      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 

of  all  dead  and  raking  shores  and  struts,  and  name  all  parts  of  the 
shore.  Make  a  drawing  |th  full  size  of  the  head  of  a  raking 
shore.     (45. ) 

11.  The  sketch  shown  below  is  the  plan  of  a  chamber  covered 
by  brick  vaulting.  Make  drawing,  showing  how  the  centring  is 
made,  and  provision  for  striking  the  same.  All  geometrical  work 
to  be  shown.     (45. ) 


12.  A  staircase  has  an  open  string.  The  two  steps  at  the  foot  of 
the  staircase,  through  which  the  newel  is  mortised,  are  "bull-nosed." 
Make  a  plati  and  elevation,  showing  the  fixing  of  the  string  to  the 
steps  ;  also  the  fixing  for  the  balusters  and  newel.     (40. ) 

13.  A  fluted  circular  column,  18  ins.  diameter  at  base,  has  a 
moulded  base  and  carved  capital.  Make  a  sketch  to  show  how  the 
base  is  built  up,  and  how  to  joint  up  the  column.  Also  make  a 
smaller  drawing  to  show  how  to  diminish  the  column.     (40. ) 

14.  Make  a  drawing  of  about  one-half  of  a  mansard  roof  ;  span, 
24  ft.  ;  trusses,  10  ft.  apart.  The  lower  part  of  the  roof  to  have  an 
inclination  of  60  degrees,  the  upper  part  J  pitch.  The  tie-beam  to 
carry  a  floor  of  7-in.  by  2-in.  joists  ;  the  underside  of  collar  to  be 
8  ft.  above  the  floor.  Indicate  all  ironwork  necessary  for  the  roof. 
Scale,  1  in.  to  1  ft.     (45.) 

15.  What  is  the  cause  of  "dry  rot"?  If  a  building  is  attacked 
by  it,  what  steps  should  be  taken  ?    (25. ) 


ANSWERS 

Chapter  IV.  (p.   105). 

1.  3o-56  cms.        2.  3716  sq.  cms.       3.  17.  61.  264. 

4.  17  ft.  nearly.  5.  6*24  ft.  =6  ft.  3  in.  nearly. 

6.  7  ft.  24  in.  10  ft.  7^  in.  20  ft.  6  in.  29  ft.  4^  in. 

7.  161  '45  sq.  ft.  8.  6  sq.  metres.  10.  405J  sq.  ft. 
11.  43-45  sq.  ft.               13.   10  ft.                                14.  4  ft.  11^  in. 

16.  137-47  sq.  ft.  16.   105|  cub.  ft. 

17.  251  cub.  ft.     £2  lOs.  7^(1.  18.   103f  cub.  ft. 
19.   163-67  cub.  ft.                                    20.  17-3  cub.  ft. 

Chapter  XII.  (p.  343). 

11.  5  cwts.  23^  lbs.      12.  4-16  inches  from  one  end.      13.  50%  more. 

14.  lOJ  cwts.  at  end  nearest  load,  4^  cwts.  at  the  other  end. 

16.  9  tons  at  one  end,  3  tons  at  the  other  end. 

16.  7  cwts.  at  one  end,  5  cwts.  at  the  other  end. 

17.  Maximum  carrying  capacity  (a)  360  cwts.,  (b)  240  cwts.     Safe 

distributed  load  (a)  144  cwts. ,  {b)  96  cwts. 

18.  5  inches  broad. 

19.  5-9  inches  deep  by  8*26  inches  broad,  or  7-4  inches  deep  by 

5-3  inches  broad. 

20.  lOJ  inches  deep  by  74  inches  broad,   or  9  inches  deep  by  74 

inches  broad  with  a  W.I.  flitch  8  inches  by  |  inch  thick. 

21.  20  inches  deep  by  15  inches  broad,  or  18  inches  deep  by  13 

inches  broad  with  a  17  inches  by  1^  inches  W.I.  flitch. 

22.  Slightly  more  than  one-half. 


494      A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


Deal,   red,   14,  211  ;   white,   14, 

211  ;  yellow,  14,  211. 
Deal  frame  saws,  130,  132-3. 
Defects  of  timber,  8. 
Deflection,  339. 
Derrick  towers,  280-1. 
Desiccation  of  timber,  8. 
Development  of  solids,  77-82. 
Diagram,bending  moment,  334-6; 

polar,  317  ;  reciprocal,  317. 
Dimensions  of  floor  boards,  210. 
Diminishing  figures,  46. 
Doatiness,  10. 
Dog,  iron,  174,  280,  297. 
Doglegged  stairs,  433,  435,  449, 

450. 
Door,   fastenings,  376 ;   frames, 

364-71 ;  framing,  348-9;  setting 

out  of  framing  for,  463. 
Doors,  346-80;   double  margin, 

358 ;      framed,     ledged     and 

braced,  346-52;  folding,  358; 

ledged,    346-7;     ledged    and 

braced,  346-7;  panelled,  353- 

69 ;  sash,  358 ;  superior,  369  ; 

vestibule,  360,  365,  367. 
Dormer  windows,  418-20. 
Dovetail,     angle     joints,     185 ; 

halved  joint,  220 ;  keys,  188  ; 

saw,  113  ;  tenon  joint,  173. 
Double  floor,  193,  201-3. 
Double  margin  door,  358. 
Double  tenon  joint,  171. 
Double  quirked  bead,  181. 
Dragon  piece,  249. 
Draw  boring,  177. 
Draw  knife,  121. 
Drawing  instruments,  21. 
Druxiness,  9. 
Dry  rot,  10,  195. 

Eaves,  of  a  roof,  216,  232;  gutter, 
232 ;  overhanging,  233. 

Edge  joints,  186. 

Electric  seasoning,  12. 

Ellipse,  73. 

Encasing  of  girders,  208. 

Enlarging  and  diminishing 
figures,  46. 

Equilateral  triangle,  28. 

Equili  brant  of  forces,  310. 

Equilibrium  of  forces,  307-8,  319. 


Expanding  brace  bit,  124. 
Excavations,  timbering  of, 


Face  marks,  461. 

Face  mould,  475. 

Fanlight,  366. 

Fascia  board,  233. 

Fasteners,  window,   407;    sasl^ 

408. 
Fastenings  for  carpenters'  }omts^ 

174. 
Felling  of  trees,  4. 
Fillets,  203. 
Fillister,  sash,  119. 
Fir,  Scotch,  14 ;  spruce,  14. 
Fireclay  blocks,  209. 
Fire-resisting  floors,  208. 
Firmer  chisel,  120. 
Fished  joint,  164 
Fixed  skylights,  412-4. 
Fixing  of,   joiners'   work,   477 ; 

window  frames,  402. 
Flitched  girders,  162. 
Flight  of  stairs,  430. 
Floor  board  joints,  210-1. 
Floor  cramps,  126,  212. 
Floor  joists,  193. 
Floors,    double,    193-201  ;     fire- 

resisting,    208 ;    framed,    193, 

203;    method  of  laying,  211; 

single,    193-4 ;   wooden  block, 

209. 
Flush  bead,  182. 
Fluting,  182. 
Flymg  shores,  287,  290. 
Folding  doors,  358. 
Force,  nature  of  a,  306. 
Forces,  parallel,  318-27 ;  parallel- 
ogram   of,    308 ;    polygon    of, 

315-7;  triangle  of,  311. 
Formula  for  wooden  beams,  337. 
Forstner  brace  bit,  124. 
Fox-wedging,  172. 
Foxiness,  10. 
Framed  floors,  193,  203. 
Framed,  ledged  and  braced  doors, 

346-52. 
Framed     and     panelled     doors, 

353-69. 
Framed  roof  trusses,  216,  220. 
Framed  and  trussed  partitions, 

260-5. 


INDEX. 


495 


TE'ramed  wooden  buildings,  266- 

72. 
IFrames,  door,  364-71 ;  window, 

402. 
IFulcnim,  318. 
IFunioular  or  link  polygon,  317. 

O-oramp,  126. 

<Jables,  240. 

<rantries,  278-9. 

Oauge,  cutting,   109 ;   marking, 

108;  mortise,  108;  thumb,  109. 
General  joiner,  152-6. 
Geometrical  definitions,  23. 
Geometrical    stairs,    433,    451, 

453-4. 
Geometry,  solid,  49. 
Gibs  and  cotters,  223-4. 
Gimlet,  122. 
Girders,      encasing      of,      208 ; 

flitched,   161-2,  204;   trussed, 

162-3  ;  wrought  iron  and  steel, 

206-7. 
Glue,  187,  189. 
Glue-blocks,  189-90. 
Gothic  roof  truss,  242-5. 
Gouges,  120. 
Graphic  determination  of  areas, 

92. 
Gravity,  specific,  342. 
Greenheart,  19. 
Greenhouses,  424-7. 
Ground  line,  50. 
Grounds,  370,  477. 
Guard  boards,  278. 
Guard  rails,  278. 
Gudgeons,  bands  and,  375. 
Guide  piles,  285-6. 
Gutter,    behind   chimney,   239 ; 

behind  parapet  wall,  234 ;  cast 

iron,  234 ;    eaves,  232 ;    lead, 

234  ;   parallel,  234  ;   tapering, 

234,  236-7. 

H-hinges,  371. 

Half  timber  work,  269-72. 

Half -space    landing,    431,    435, 

444. 
Halved  joints,  182,  262. 
Halved  and  cogged  joint,  220. 
Halving,  166-8. 
Hammer-headed  roof  truss,  245. 


Hammer-headed  key,  167,  188. 

Handrail  bolt,  183,  456. 

Handrails,  451;  ramped,  456; 
swan-neck  in,  456. 

Hanging  of  sashes,  396-9. 

Hardwcxxi  trees,  4. 

Haunched  tenon  joint,  170,  348. 

Heading  joints,  183,  211. 

Heart  shakes,  9. 

Heartwood,  2. 

Heptagon,  35. 

Herring-bone  bridging,  200. 

Hexagon,  34. 

Hinged  skylight,  414-8. 

Hinges,  backflap,  373 ;.  bands 
and  gudgeons,  375  ;  butt,  372 ; 
parliament,  373 ;  pew  or  egg- 
joint,  373 ;  projecting  butt, 
372  ;  rising  butt,  372 ;  spring, 
374. 

Hip,  216,  246. 

Hip  rafters,  216 ;  backing  of, 
251 ;  lengths  and  bevels  of, 
248-9. 

Holdfast,  bench,  126. 

Hollow-ground  saws,  142. 

Horizontal  log  frame  saws,  132, 
134. 

Horizontal  trace,  62. 

Hospital  Ught,  396,  398. 

Hot-air  seasoning,  8. 

Housed  joint,  68-9,  198. 

Hyperbola,  76-7. 

Inclined  forces,  317. 

Inclined  planes,  62. 

Injury  caused  by  animals,  10. 

Inscribed  figures,  36. 

Inside  door  frames,  368. 

Instruments,  draMdng,  21. 

Intertie,  264. 

Iron,  bolts,  222 ;  columns,  204-5 ; 
dowels,  366;  dog,  174,212,280, 
297 ;  girders,  206 ;  planes,  117 ; 
purlins,  218. 

Isosceles  triangle,  28 

Jack  plane,  115. 

Jack  rafter,  216 ;    lengths  and 

bevels  of,  253. 
Jarrah  wocfd,  19. 
Jib  orane,  281. 


496       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


-S'v 


Joiners'  work,  fixing  of,  477. 

Joint,  angle,  184  ;  between  king 
post  and  tie-beam,  223 ;  be- 
tween tread  and  riser,  437  ; 
bird's-mouth,  220;  bridle,  262; 
butt,  183  ;  chase  mortise,  203  ; 
clamped,  189 ;  cogged,  202, 
220;  dovetail,  185,  220;  at 
foot  of  principal  rafter,  221  ; 
halved,  182,  220,  262  ;  at  head 
of  principal  rafter,  222 ;  at 
head  of  queen  post,  226 ;  mor- 
tise and  tenon,  169,  180,  348, 
463;  rule,  188,  374;  stump 
tenon,  262,  348;  tusk-tenon, 
171,  198,  225. 

Jomt  bolt,  176,  183,  223-4. 

Jointing  plane,  117. 

Joints  and  fastenings,  158,  174. 

Joints,  classification  of,  159 ; 
'L't;^^t  floor  board,  210 ;  heading,  183 ; 
housed,  184,  198 ;  in  door 
framing,  348-9  ;  keyed,  188-9 ; 
lengthening,  182;  mitred,  184, 
467-8  ;  scarfed,  182 ;  scribed, 
185. 

Joists,  bridging,  194 ;  ceiling, 
193,  195,  202,  218,  232;  di- 
mensions of,  193 ;  trimming, 
197. 

Key,  hammer- headed,  182,  188. 
Keyed  joint,  167,  188-9. 
King-bolt,  229. 
King  post  truss,  221. 
Knots,  8. 

Kyan's  process  of  seasoning 
timber,  12. 

Ladders,  275. 

Laminated  string,  440. 

Lantern  lights,  420. 

Lap  dovetail  joint,  185. 

Lapped  joints,  164,  169. 

Larch,  16. 

Latches,  door,  376. 

Lay  lights,  424. 

Lajdng  floors,  method  of,  211. 

Lead,  covered  roofs,  240 ;  drip, 

238  ;  gutter,  234  ;  roll,  238. 
Lean-to  roof,  216. 
Lodged  and  braced  doors,  346-7. 


Ledgers,  277. 

Lengths  and  bevels  of,  oommon 
rafters,  246-7  ;  hip  and  valley 
rafters,  248-9 ;  jack  rafters, 
253. 

Lengthening  joints,  163,  182. 

Levers,  318. 

Lewis  or  rag  bolt,  177. 

Line  of  nosings,  430. 

Linings,  apron,  444 ;  jamb,  368 ; 
splayed,  472-3. 

Loaded  beams  with  stress  dia- 
grams, 319-27. 

Locks,  door,  376  ;  mortise,  377. 

Log  frame  saw,  horizontal,  132-4 ; 
vertical,  129-31. 

Machines,  band  saw,  135-7  ;  cir- 
cular saw,  138-41  ;  cross-cut 
saw,  133-5 ;  deal  frame  saw, 
130,  132-3;  horizontal  log 
frame,  132-4;  mortising,  151-3; 
moulding,  148  ;  panel  planing, 
146 ;  planing,  144-7 ;  saw 
sharpening,  142-4 ;  surface 
planing,  145  ;  tenoning,  150  ; 
thicknessing,  146  ;  vertical  log 
frame,  129-31 ;  vertical  spindle 
moulding,  148. 

Mahogany,  17. 

Mansard  roof  truss,  242. 

Maple,  18. 

Margin  template,  436-7. 

Marking  gauge,  108. 

Masons'  scaffold,  278. 

Match  boarding,  186. 

Measurement  of,  angles,  22,  108 ; 
length,  22. 

Measuring  and  testing  tools, 
107-11. 

Mechanics  of  carpentry,  306-45. 

Medullary  rays,  2. 

Mensuration,  85-106. 

Method  of,  calculating  timber, 
100  ;  laying  floors,  211. 

Metric  measurement,  22,  85. 

Mitre,  block,  467;  box,  467; 
template,  466. 

Mitred  joint,  184-5,  356,  467-8. 

Mitring,  466. 

Moulding,  raking,  468-9. 

Mouldings,  181  ;  band,  .368,  404. 


INDEX. 


497 


Nails,  179. 

Natural  seasoning,  7. 

Needle  shores,  287-9. 

Newel  post,  439,  450,  452,  455. 

Noden    Bretenneau   method    of 

seasoning  timber,  12. 
Nogging,  briok,  265. 
Northern  pine,  14. 
Nose  bit,  123. 
Nosings,  line  of,  430. 
Notch  boards,  447. 

Oak,  16. 

Oblique  planes,  62-9. 

Obtuse,  angle,  23 ;  angled  tri- 
angle, 28. 

Octagon,  35. 

Ootahedix)n,  52. 

Offsets,  196. 

Oilstone,  119. 

Open  newel  stairs,  432,  449, 
4512. 

Oregon  pine,  16. 

Overhanging  eaves,  233. 

Oversailing  courses,  196. 

Pad  saw,  1 14. 

Paint,  11. 

Panel,  plane,  117;  planer,  146; 

saw,  112. 
Panelled  doors,  353-69. 
Parabola,  76-7. 
Parallel  forces,  318. 
Parallel  gutter,  234. 
Parallelogram,  32. 
Parallelogram  of  forces,  308. 
Parapet  wall,  gutter  behind  a, 

234. 
Paring  chisel,  120. 
Parliament  hinge,  373. 
Pendentive  cradling,  476-7. 
Periphery  of  a  circle,  25. 
Pew  or  egg- joint  hinge,  373. 
Piles,  285-6. 
Pillars,  cast-iron,  204. 
Pitch  board,  436. 
Pitch  pine,  15,  211. 
Pivoted  or  swing  sash,  386-8. 
Plane  geometry,  21. 
Plane  iron,  115. 
Planes,    inclined,    62 ;    oblique, 

62-9. 

M.C.J.  2 1 


Planing  machine,  144-7. 

Plough,  118. 

Plugs,  wooden,  178. 

Plumb,  bob,  110;  line,  110; 
rule,  110. 

Polar  diagram,  317. 

Pole  plate,  234-5. 

Poling  boards,  282. 

Polygon,  33 ;  area  of  a,  94. 

Preservation  of  timber,  11. 

Princess  post,  227. 

Principal  rafter,  221,  226. 

Principles  governing  the  con- 
struction of  joints,  158. 

Prism,  51. 

Projecting  butt  hinges,  372-3. 

Projection,  of  lines,  58-61 ;  of 
solids,  53-7 ;  orthographic,  50. 

Proportion,  41. 

Proportion  of  tread  to  riser, 
433-4. 

Protractor,  23. 

Pugging,  201. 

Pulleys,  240-2. 

Purlins,  216-8;  iron,  218. 

Putlogs,  277. 

Pyramid,  52. 

I^amid  roof,  246. 

Quadrilateral  figures,  32. 
Quadrants,  408,  427. 
Qualities  of  good  timber,  13. 
Quarter  space  landing,  430,  435, 

444,  451,  454. 
Queen-post  roof  truss,  225-8. 
Quirked  bead,  181. 

Rafter,  common,  215,  217,  246-7 ; 

hip,    216,    246,    248-9;    jack, 

216,  253 ;  principal,  221-2, 246 ; 

valley,  216,  246,  248-9. 
Rag  or  lewis  bolt,  177,  366. 
Raking,       mouldings,       468-9 ; 

shores,  287. 
Ramped  handrail,  456. 
Rebate  plane,  118. 
Reciprocal  diagram,  317. 
Rectangle,  33. 
Red  deal,  14,211. 
Reeding,  182. 
Relative  density,  342. 
Resultant  of  forces,  307. 


498       A  MANUAL  OF  CARPENTRY  AND  JOINERY. 


Rider  shore,  290. 

Ridge,  215. 

Ridge  piece  or  tree,  215. 

Right  angled  triangle,  28. 

Right  angles,  23. 

Rindgalls,  10. 

Rings,  annual,  2. 

Rip  saw,  111-2. 

Rising  butt  hinges,  372. 

Rod,  setting  out,  462-5. 

Roof,  applied  geometry  in  the 
construction  of  a,  246 ;  couple, 
216 ;  lean-to,  216 ;  lead  covered, 
240;  lights,  412;  pyramid, 
245;  turret,  245,  253-5;  zinc 
covered,  240. 

Roof  truss,  collar  beam,  219 ; 
framed,  216-20;  Gothic,  242-5 ; 
hammer  beam,  245 ;  king  post, 
221 ;  lattice  or  bow-string, 
241 ;  Mansard,  242 ;  queen 
post,  225-8. 

Rosewood,  19. 

Rot,  dry,  10,  195. 

Rough  carriages,  444-5. 

Round-ended  step,  432,  442-3. 

Router,  119. 

Rule  joint,  188,  374. 

Sapwood,  2. 

Sash  and  frame  window,  389-96. 

Sash,  cramp,   125 ;   doors,  358 

fasteners,  408-9  ;  fillister,  119 

lifts,  408-9  ;  pivoted  or  swing 

386-8. 
Sashes,     381,     392;     casement 

384-6  ;  horizontal  sliding,  389 
Saw-kerfing,  471. 
Saw-set,  113. 

Saw-sharpening  machine,  142-4. 
Saw-teeth,  112,  141. 
Saws,  111-4;  machine,  129-42. 
Scaffold,  274;  bricklayers',  276-7 

boards,  277;  masons',  278. 
Scaffolding  trestle,  274-5. 
Scalene  triangle,  28. 
Scales,  42. 

Scarfed  joint,  165,  182. 
Scotch  fir,  14. 
Screws,  180. 
Screws,  coach,  175,  280. 
Scribed  joint,  185. 


Scribing,  184,  356,  466.  

Seasoning  of  timber,  5-8 ;  chem-^^* 

cal,  12, 
Second  seasoning,  7. 
Secret  dovetail  joint,  185. 
Secret  nailing,  478. 
Secret  screwing,  370-1,  478. 
Sections,  69-77. 
Sector  of  a  circle,  25. 
Segment  of  a  circle,  24. 
Sequoia  pine,  16. 
Set  on  a  saw,  112. 
Set  squares,  21. 
Setting  out,  curve  for  segmental 

arch,  295 ;  door  framing,  463 ; 

panelled    framing,     462;     of 

stairs,  434;   rod,  462,  464-5; 

window  frames,  465. 
Shakes  in  timber,  9. 
Sharpening,    of    saws,    114;    of 

planes,  119. 
Shearing  stress,  161,  331, 
Shed  roof,  228. 
Sheeting,  283. 
Sheet  piles,  285-6. 
Shell  bit,  123. 
Shop  window,  402-3. 
Shoring,  287-92. 
Shrinkage  of  timber,  4. 
Shutters,  window,  405. 
Silver  grain,  2,  5,  17. 
Single  floor,  193-4. 
Skids,  7. 

Skirting  boards,  478-9. 
Skylights,  412-8. 
Sleeper  walls,  195. 
Sliding  bevel,  108. 
Sliding  window  shutters,  406. 
Slip  feathers,  356. 
Smoothing  plane,  116. 
Snipe  bill,  177. 
Snow  boards,  240. 
Socketed  chisels,  121. 
Soffit  boarding,  234. 
Soft  wood  trees,  4. 
Solid  georaetrv,  49. 
Solid    or    cubic    measurement, 

100-5. 
Solids,  development  of,  77-82. 
Sound  boarding,  201. 
Spandrel  framing,  433,  444. 
Spars,  215. 


INDEX 


499 


Specific  gravity,  342. 

Spectators'  stands,  299-303. 

Sphere,  52. 

Spikes,  178. 

Spirit  level,  109. 

Splayed  linings,  472-3. 

Split  bill,  177,  366. 

Spokeshave,  119. 

Sprigs,  179. 

Spring  hinges,  374. 

Square,  33. 

Square  root,  88. 

Staff  bead,  181. 

Staircase  work,  430-59. 

Stairs,  doglegged,  432,  449-50; 

erection  of,  444 ;  flight  of,  430 ; 

geometrical,  433,  451,  453-4 ; 

open  newel,  432,  449,  451-2; 

well    of,    432 ;    winder,    432, 

448-9. 
Stirrup  iron,  204,  223. 
Stone  template,  207. 
Storey  rod,  434. 
Straight  edge,  108. 
Straining,  beam,  226 ;  sill,  226. 
Straps,  iron,  175. 
Strength  of  wooden  beams,  331. 
Stress,  in  buckling  chain,  312-3  ; 

compression,     331  ;     in    wall 

bracket,  313-4 ;  shearing,  161, 

331-2;  tension,  331. 
Stress  and  strain,  160,  331, 
Stress  diagram,  for  loaded  beams, 

319-27  ;  for  roof  truss,  326-31. 
Stresses  in  beams,  160,  331. 
String  board,  432-9  ;  bracketed, 

432 ;     close,    432 ;     cut    and 

mitred,  432  ;  laminated,  440  ; 

staved,  440  ;  veneered,  440-2. 
Struts,  163,  221,  282. 
Strutting,  200. 
Studs,  259. 

Stump  tenon  joint,  174,  262,  348. 
Superior  doors,  362,  369. 
Surface  planer,  145. 
Swage  saw,  142. 
Swan  neck  in  handrail,  456. 
Swiss  bit,  123. 
Sycamore,  18. 

Table  or  rule  joint,  188. 
Tacks,  179. 


Tangent,  25. 

Tapering  gutter,  234,  236-7. 

Tarring,  11. 

Teak,  17. 

Tee  or  cross  garnet  hinges,  371. 

Tee  square,  21. 

Teeth,  saw,  112,  141. 

Template,  margin,  436-7  ;  mitre, 

466 ;  stone,  207. 
Tenon  saw,  113. 
Tenoning  machine,  150. 
Tension  stress,  331. 
Teredo  navalis,  10. 
Termites,  11. 
Testing  tools,  108. 
Tetrahedron,  52. 
Thicknessing  machine,  146. 
Thumb  gauge,  109. 
Timber,  crossgrained,  9  ;  defects 

of,  8  ;  methods  of  calculating, 

100 ;     preservation     of,     11  ; 

seasoning  of,  5,  6  ;  shrinkage 

of,  4 ;  varieties  of,  13. 
Timbering  of,  excavations,  285  ; 

trenches,  282-4. 
Tools,    107-28;    boring,    122-4; 

cutting,  111-21  ;  testing,  108- 

11. 
Torus  moulding,  182. 
Traces  of  a  plane,  62. 
Trammel  pins,  109. 
Trapezoid,  33. 
Trapezium,  33. 
Traveller,  280. 
Tread  and  riser,  joint  between, 

437  ;  proportions  of,  433-4. 
Trees,  1,  4. 
Trenails,  177,  271. 
Triangle  of  forces,  311. 
Triangles,  28  ;  area  of ,  91. 
Trimmer,  197. 
Trimmer  arch,  197-9. 
Trimming  of  floor  joists,  197. 
Trimming  of  roofs,  240. 
Trueing-up  of  material,  461. 
Truss,  composite,  229-31 ;  Gothic, 

242-5 ;    hammer    beam,    245 ; 

king-post,    221 ;    latticed    or 

bow-string,  241 ;  Mansard,  242 ; 

queen-post,  225-28. 
Trussed  girders,  162. 
Trying  plane,  116. 


500       A  MANUAL  OF  CARPENOftlY  AND  JOINERY. 


Try  square,  108. 
Turret  roofs,  245,  253-5. 
Tusk  tenon  joint,  171,  198,  204. 
Twisted  fibres,  9. 

Units,  British  and  metric,  86. 
Units  of  length,  85. 
Upsets,  10. 

Valley  rafter,  216,  246. 
Varieties  of  timber,  13. 
Veneered  string,  440-2. 
Venetian  window,  396-7. 
Vertical  log  frame  saw,  129-31. 
Vertical  spindle,  148. 
Vertical  trace,  62. 
Vestibule  doors,  360,  365,  367. 

Waling  pieces,  283. 

Wall  piece,  '288. 

Wall  plates,  195-6,  215 

Walls,  sleeper,  195. 

Walnut,  18. 

Water  seasoning,  8. 

Wedging,  176 ;  folding,  212, 293 ; 

fox,  172. 
Well  of  stairs,  432. 
Wet  rot,  10. 
White  deal,  14,  211. 
Winder  stairs,  432,  448-9. 


Winders,  430. 

Winding  strips,  108. 

Window,  fastenings,  407 ;  linings, 
402 ;  shutters,  405-6. 

Window  frames,  fixing  of,  402. 

Windows,  381-411  ;  bay,  399- 
401 ;  casement,  384-6 ;  dormer, 
418-20 ;  sash  and  frame,  389- 
96 ;  shop,  402-3 ;  setting  out 
of,  465  ;  Venetian,  396-7. 

Wire  nails,  179. 

Wooden,  block  floors,  209 ; 
centres,  293-9;  floors,  193- 
214  ;  framed  buildings,  266  ; 
pins,  176;  plugs,  178,  366; 
roofs,  215-58. 

Wooden  beams,  strength  of,  331. 

Wood-working  machinery,  129. 

Workshop,  arrangement  of,  460 ; 

W practice,  460. 
reathed  string,  432,  40. 
Wrought,  clasp  nails,  179  ;  clout 
nails,  179  ;   iron  girders,  206  ; 
iron  straps,  222-4. 

Yellow  deal,  14,  211. 
Yellow  pine,  15. 

Zinc  covered  roofs,  240. 


GLASGOW  :    PRINTED  AT  THE  UNIVERSITY  PRESS  BY  ROBERT  MACLEHOSK  AND  CO.  LTD. 


BY  THE  SAME  AUTHOR. 

Globe  Svo,     2S,  6d, 

With  623  Illustrations. 

BUILDING    CONSTRUCTION 
FOR    BEGINNERS 

By  J.  W.  RILEY, 

Lecturer  in  Descriptive  Geometry,  Building  Construction,  Carpentry 
and  foinery,  at  the  Municipal  Technical  School^  Rochdale, 


Works  by  F.   CASTLE, 

Machine    Construction    and    Drawing.     Globe 
4to.     4s.  6d. 

"Workshop  Mathematics.     Parts  I.  and  II.     Globe 
8vo.     IS.  6d.  each. 

Mathematical   Tables.     Crown  8vo.     Sewed.     2d. 

Elementary     Practical     Mathematics.       Globe 
8vo.      3s.  6d. 

A   Manual  of   Practical   Mathematics.      Globe 
8vo.     6s. 

Practical  Mathematics   for   Beginners      Globe 
8vo.     2s.  6d.     Key,  5s.  net. 


London:    MACMILLAN   AND   CO.,   Limited. 


Macmillan  and  Co/s  Publications* 


Handicraft  and  Design.  By  W.  A.  S.  Benson. 
Crown  8vo.     5  s.  net. 

The  Grammar  of  "Woodwork.  A  Graduated 
System  of  Manual  Training  for  Elementary,  Secondary,  and 
Technical  Schools.  Designed  for  the  Pupils  of  the  White- 
chapel  Craft  School  by  Walter  E.  Degerdon.  4to.  3s. 
Sewed.     2s. 

The  Mechanism  of  "Weaving.  By  Thomas  W. 
Fox.     Crown  8vo.     7s.  66,  net. 

Manual  Training ;  "Woodwork.  A  Handbook  for 
Teachers  By  George  Ricks.  With  275  illustrations. 
Crown  4to.     7  s.  6d. 

Cotton  Spinning.  By  William  Scott  Taggart.  With 
illustrations.  Second  Edition.  Three  vols.  Crown  8vo. 
— Vol.  I.  Including  all  processes  up  to  the  end  of  carding. 
4s.  net — Vol.  II.  Including  the  processes  up  to  the  end  of 
fly-frames.     4s.  net. — Vol.  III.     los.  net. 

Cotton  Machinery  Sketches.  By  William  Scott 
Taggart.     Super  Royal  8vo.     Sewed.     2s.  6d. 

Woollen  Spinning.  A  Text-book  for  Students  in 
Technical  Colleges,  and  for  skilful  practical  men  in  Woollen 
Mills.  By  Charles  Vickerman.  Illustrated.  Crown  8vo. 
6s.  net. 

Varied  Occupations  in  Weaving  and  Cane  and 
Straiv  "Work.     By  Louisa  Walker.     Globe  8vo.     3s.  6d. 

Varied  Occupations  in  String  Work.  By  Louisa 
Walker.     Globe  8vo.     3s.  6d. 


London:    MACMILLAN    AND    CO.,    Limited.